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Post by rexton on Jun 15, 2020 18:30:21 GMT
This is a unique blog to Audio Addicts forum. The idea behind this blog is to develop a cheap as chips Chinese system which will hopefully evolve and showcase the odd bit bought from eBay. No doubt there will be cheaper components available but this is all about fun and seeing what we can get out of these ebay wonders. The main emphasis on this system and blog is to spend as little as possible in upgrading and modding the components. I will from time to time scavenge bits from my spares box in the garage and wherever possible swap or recycle things which can be used within the system. View this blog as a fun, skinflints, guide to building a decent cheapy system!
My first component is the venerable Little Bear P-51 valve pre-amp which uses x2 6J1 valves. It cost a grand total of £16 delivered. This little pre-amp is brilliant for introducing audio geeks into the fine old art of tube rolling.
You can mess around with power supplies, batteries and linear power supplies. I own all these PSU's so this should be fun when trialling them on the components in the system. The P51 takes 12V's this is quite useful it's very easy to go to cash converters and offer them a couple of quid for discarded laptop PSU's  You'll find many 6J1 variants doing the rounds on ebay, you can even go to Watford valves and find a whole section dedicated to selling upgrade 6J1 and variants. I initially decided to but x2 Mullard M8100 from Watford Valves but this would have cost me nearly £28. So, being a tight git I scoured eBay and managed to find two delivered for £18, a £10 saving.  . So far we've spent £34 on a preamp a pair of premium military grade valves.
My next component is another component that's no stranger to this forum, the HIFI Class 2.0 Stereo Audio Digital Amplifier TPA3116 Advanced 2×50W Breeze Amp
I'd seen a thread about this on the forum and decided to pull the trigger. Originally priced at £20.60 + £1.19 postage. My offer was accepted at £18 + postage, so £19.19. A saving of £2.60. See I told you this was going to be a tight arse system.  . You can buy these amps cheaper but I liked the case, so probably I waste of cash. There are plenty of youtube vids on this amp and generally it can be run on anything from 9 to 24V, distortion does increase with higher voltages, so again it's looks like we are going to have some fun with playing around with PSU's. I've now got a 4 week wait for the TPA3116 but that's ok as it gives me time to hunt around office desks for old laptop PSU's and my garage for spares to cannibalise.
Total spend so far :-
Mullard M8100 valves x2 £18 Little Bear P51 £16 Breeze Audio TPA3116 £19.19
GRAND TOTAL £53.19
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Post by jimbo on Jun 15, 2020 18:38:24 GMT
Great little project Andy. Like it.
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Post by stryder5 on Jun 15, 2020 20:46:41 GMT
I thought the P51 12v supply was AC, won’t the laptop chargers be DC?
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Post by rexton on Jun 15, 2020 21:15:29 GMT
I thought the P51 12v supply was AC, won’t the laptop chargers be DC? Who knows! That's the fun bit, I'm making it up as I go along!! This system is so cheap it doesn't matter it if blows up!! Thanks for the heads up. |
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Post by firebottle on Jun 16, 2020 7:51:55 GMT
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Post by antonio on Jun 16, 2020 17:23:56 GMT
You don't need a pre, it's a one input amplifier. Course you could try and find a cheap as chips power amp.
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Post by rexton on Jun 18, 2020 19:58:19 GMT
Part 2 - Scrounge around the attic!!!
My practice has some old junk deposited in the attic from the previous owner. Today I decided to have a little look to see what I could find  . Didn't find a great deal TBH.
I found an old 9V PSU (AC) which could be of some use and a set of leads which looks like they could be converted into a pair of IC's. Total cost = BUGGER ALL which is well within the spirit of the thread! The IC's are "gold" plate , probably coloured in with a gold pen, the plating is that thin it's laughable and probably very Chinese. The 9V PSU may be very useful in driving the TPA3116 to low volume levels but at lower distortion levels, and once again it's FREE, again well within the parameters of our skinflint system.
I now just need to find a CCCC power amp and I purchased this the Douk Audio HiFi FU32 Tube Amplifier, £96.74 assembled, with tubes, and delivered.
CCCC system and running costs
Mullard M8100 valves x2 £18
Little Bear P51 £16
Breeze Audio TPA3116 £19.19
9V PSU - £FREE
IC'S - £FREE
Douk Audio HiFi FU32 Tube Amplifier £96.74
GRAND TOTAL £149.93
It's just a waiting game now for everything to turn up.
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Post by jimbo on Jun 18, 2020 20:39:32 GMT
Exciting stuff Andy, the real surprise will be how it sounds?
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Post by rexton on Jun 18, 2020 21:05:53 GMT
No idea Jim it's another 6J1 amp with the FU32 valve, now this is a real power house of a valve, 2.5W output  ) |
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Post by jimbo on Jun 19, 2020 5:33:02 GMT
No idea Jim it's another 6J1 amp with the FU32 valve, now this is a real power house of a valve, 2.5W output ) Mmmm maybe drive some small computer speakers? |
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Post by rexton on Jun 19, 2020 7:04:58 GMT
Maybe or even some high efficiency horns? Can you imagine these little amps driving massive 15" horns, it's not going to really be that effective but it will be lots of fun. I've got 2-3 pairs of speakers in my wardrobe that I hardly use so I can have some fun using them and I can also have some fun tube rolling the FU32 tube, I mean come on, how many people run one of these www.r-type.org/exhib/aaa1814.htm ?? Part of the fun is that it's supposed to be a cheap Chinese system and these valves are pretty cheap to pick up and they also look very very cool (well to me they do). |
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Post by jimbo on Jun 19, 2020 9:10:35 GMT
Maybe or even some high efficiency horns? Can you imagine these little amps driving massive 15" horns, it's not going to really be that effective but it will be lots of fun. I've got 2-3 pairs of speakers in my wardrobe that I hardly use so I can have some fun using them and I can also have some fun tube rolling the FU32 tube, I mean come on, how many people run one of these www.r-type.org/exhib/aaa1814.htm ?? Part of the fun is that it's supposed to be a cheap Chinese system and these valves are pretty cheap to pick up and they also look very very cool (well to me they do). You could pop it inside some large horns as part of the crossover unit! |
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Post by rexton on Jun 19, 2020 9:31:06 GMT
Bit more info on the amp I've bought, 8% THD @ 2-3 Watts !!!!!!!!!!!!
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Post by rexton on Jun 20, 2020 10:50:06 GMT
Bit bored today so I'm going to have a rummage in the spares box to see what we can use on the CCCC system.
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Post by rexton on Jun 20, 2020 17:38:31 GMT
 Here's some odds and sods I found in the spares box. We've got an Anker battery PSU unit. I managed to find a six gang mains blocks, some silver plated plugs + silver plated fuses. Several small ferrite chokes, some Eichmann silver bullets, some pure silver for rewiring, x3 MM cartridges (technics, shure, ADC), some 10mm Sorbothane which could be used to make decoupling pads. I managed to find a couple small off-cuts of van-damme 2.5mm speaker cable, some Duelund cable, and some 2-core mains lead which can double up as speaker cable. Finally I managed to find a few 0.5m off-cuts of Belden 18364 power cable. I'm actually quite surprised by this little haul. This means that the components should have shielded mains cables with some nice silver plated plugs. The ferrite chokes might be useful for in-going PSU mini cables. The speaker cables speak for themselves and might provide an interesting nights comparison. I'll probably put a nice plug on the six-gang extension and I'll use my pillar drill to make some nice sorbothane de-coupling feet for the various units. The anker unit could make for interesting listening when comparing against a linear PSU or even straight from the National Grid.
As an aside I've been looking at cheapy MM phonostage units and came across this at £13.50
Fully assembled and delivered, might need a little modding to add a ground post but that's no big deal. I have seen other phonostage units with MM/MC capability, so tonight's task is to assess the merits of the various cheapy units and see what tickles my fancy.
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Post by rexton on Jun 20, 2020 17:44:02 GMT
Here's a quick update of the running costs.
CCCC system and running costs
Mullard M8100 valves x2 £18
Little Bear P51 £16
Breeze Audio TPA3116 £19.19
9V PSU £FREE
IC'S £FREE
Douk Audio HiFi FU32 Tube Amplifier £96.74
Speaker cable (2core/VanDamme/Duelund) £FREE
Belden/Silver plug power cables £FREE
Ferrite chokes £FREE
MM carts (assuming they work) £FREE
Sorbothane offcuts £FREE
Silver offcuts + Teflon (salvaged) £FREE
GRAND TOTAL £149.93
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Post by jimbo on Jun 20, 2020 17:46:42 GMT
The free stuff definitely helps keep the cost down! |
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Post by rexton on Jun 20, 2020 19:55:28 GMT
The free stuff definitely helps keep the cost down! TBH I'll only be using the free stuff when I've got a good idea of the sonic signature of the system "as-is", the fun begins when we start messing around changing power leads, PSU's valves etc. As stated, it's just fun.
Tonight I made my final purchase, a MM phonostage. I purchased this one for many reasons. Firstly I get a PSU so I don't have more expenditure. The case is aluminium so should offer some shielding, and it was also incredibly cheap at £19.96 delivered. I could have had a MM/MC phonostage at £26 but I didn't want the expense of having to purchase a cheap MC cartridge and I've an abundance of Shure cartridges which can be used. Here's what I purchased.
CCCC system and running costs
Mullard M8100 valves x2 £18
Little Bear P51 £16
Breeze Audio TPA3116 £19.19
9V PSU £FREE
IC'S £FREE
Douk Audio HiFi FU32 Tube Amplifier £96.74
Speaker cable (2core/VanDamme/Duelund) £FREE
Belden/Silver plug power cables £FREE
Ferrite chokes £FREE
MM carts (assuming they work) £FREE
Sorbothane offcuts £FREE
Silver offcuts + Teflon (salvaged) £FREE
Little Bear T8 MM phonostage £19.96
GRAND TOTAL £169.89
The whole system could have been £58.14 cheaper if I had not purchased the Mullard valves, TPA3116 or MM phonostage. I decided I wanted vinyl as my source, I could have used CD but I don't think I'd have enjoyed tweaking as much. All in I could have spent £111.75 but I don't think I would have had as much fun. It's now a waiting game for all the components.
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Post by jimbo on Jun 20, 2020 20:30:18 GMT
Speakers may blow the budget unless you buy second hand?
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Post by rexton on Jun 20, 2020 20:43:15 GMT
I'll probably use my Celestion Ditton 15's out of my REAL SOUND system for starters.
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Post by rexton on Jun 22, 2020 20:31:02 GMT
Mullard M8100's turned up today, they are tiny!
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Post by rexton on Jun 26, 2020 20:46:54 GMT
The CCCC system now lives. Currently only playing CD as main source as I still awaiting the Little Bear MM phonostage. Cabling is a bit botched, the six gang has been salvaged from the garage and I fitted a silver plated plug. The IC's have been salvaged from an old JVC digital camcorder. The PSU for the preamp came from an office drawer, lord knows what it powered. Speaker cabling came from some Dunelund DCA16GA offcuts I had lying around in the garage. Speakers are my old Celestion Ditton 15's. Overall not a bad sound It's quite under powered but that's what gives it a little charm. Crank the volume up and it gets stupidly distorted. It makes you listen and concentrate at low levels. The 15's are the most sensitive speakers I own I may have to start haunting some of the charity shops when they open and see if we can snag a pair of something more sensitive. So two things from the off. The preamp sounds better with a full 12V I dicked around for 30 minutes with a 10V supply and secondly the cheapy chinese 6J1 valves are ok but things sounded much better when I changed them for the Mullard M8100's. It's really too hot and too late to be too much dicking around with valve amps but at least we are up and running.
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Post by rexton on Jun 28, 2020 17:37:57 GMT
One of the reasons the CCCC system came about was to get into cheap valve rolling. Mullard produce a premium valve in the guise of the M8100 which replaced the EF95 as a ruggised version. Amazingly the cost of these virtually unused valves has steadily started to increase with the onset of the Little Dot amplifiers. A valve that could be bought for a couple of pounds is now costing £8 if your lucky. The 6J1 and is Russian variants can be bought pretty cheaply from the Ukraine and China and you can even search the US of A and find variants for a few bux. My power amp uses a Chinese knock off valve called the FU-32, a direct copy of the GU-32, now you don't see many of these up for sale. I bought a Russian RY-32 valve military new old stock for a grand total of £12.80 delivered. I'm quite happy with the system so far, it does have it's limitations but I find these charming and fun. I'll post more later tonight with some pics.
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Post by jimbo on Jun 28, 2020 18:13:27 GMT
All interesting stuff Andy, nice challenge to give yourself. I am sure you will get a system together that works well?
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Deleted
Deleted Member
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Post by Deleted on Jun 28, 2020 18:22:27 GMT
One of the reasons the CCCC system came about was to get into cheap valve rolling. Mullard produce a premium valve in the guise of the M8100 which replaced the EF95 as a ruggised version. Amazingly the cost of these virtually unused valves has steadily started to increase with the onset of the Little Dot amplifiers. A valve that could be bought for a couple of pounds is now costing £8 if your lucky. The 6J1 and is Russian variants can be bought pretty cheaply from the Ukraine and China and you can even search the US of A and find variants for a few bux. My power amp uses a Chinese knock off valve called the FU-32, a direct copy of the GU-32, now you don't see many of these up for sale. I bought a Russian RY-32 valve military new old stock for a grand total of £12.80 delivered. I'm quite happy with the system so far, it does have it's limitations but I find these charming and fun. I'll post more later tonight with some pics. Pity it's not the GU-29. You could have marveled at the thought of it being used in the Russian MIG-15 Fighter. |
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Post by rexton on Jun 28, 2020 19:40:29 GMT
Second post of the night, blimey! I've had this little working now for two days and I've been using a myriad of bits and pieces scrounged from various cellars, lofts,garages and office drawers. I've been having lots of fun mucking around. So now it's time for a few observations. The FU-32 power amp was the cheapest amp I could find and I wanted something valve based so I could experiment with cheap valves and experience a new valve type. The FU-32 is a knock off copy of the GU-32 and boy you can tell. The supplied FU-32 valve had pins coated in very very thin nickel which flaked away. The output of the FU32 isn't massive so you'll need some efficient speakers, my Celestion Ditton 15's don't fall into that category but I can play at a reasonable level and get a decent wide soundstage which for the power output is pretty good. The Douk Audio HiFi FU32 has several speaker outputs through 2/4/8 Ohms, I went for 8 Ohms hoping this would help the amp's output. The Douk Audio HiFi FU32 has no speaker binding posts as such just several simple plastic locking posts which are tiny and mean your going to be stumped if you want to use big fat ass speaker cables. You'll struggle to get anything bigger than 16GA into those sockets, and there lies your problem. I tried Duelund 16GA and it sounded pretty good. I later swapped to something else (more later). The Douk Audio HiFi FU32 has no IEC so you've got to hard wire you power lead into the same type of plastic binding post as the speakers, again, forget using audiophile screened cable or something from Belden. My power cable was salvaged from a 5 meter run of cable which used to be attached to our old dish washer. I attached a silver plated plug and a silver plated fuse and that's about as modded as it gets for the PSU into the power amp. The really cool thing about the power amp is the variety of valves out their at cheap(ish) prices. I've already been bitten by the bug and started hunting for JAN versions of American 832A valves. I'm trying to keep the cost of this project down, a fun parameter for both my wallet and myself. I've learned in the past not to piss around and generally buy military spec valves as they are generally less microphonic and built well beyond the needs of a tiny valve amp. I hope to have fun over the next few weeks skulking around ebay.com and seeing what we can purchase from the states. I also forgot to mention the system is SILENT, no humming whatsoever. The Little Bear P51 pre-amp is slightly better constructed with very thinly gold plated RCA sockets. It's very simple audio in, audio out and a 12V power supply. I've played around with various PSU's with this little pre-amp and have found that it's responds best with 15V from a Linear PSU, yes I bought one of the cheapo Chinese Linear PSU's 2-3 years ago when you could get them for <£40 delivered. The P51 hates Walwart PSU's and I noticed hideous distortion even at low listening levels. The distortion is still around but only when you turn the thing up to full volume. I can still listen at decent levels without distortion but what do you expect from a power amp with less than 3 watts output going into an 8 Ohm speaker which needs a minimum of 10 watts !!??!! I did put a couple of ferrite chokes around the power input into the P51, I have no idea if they have helped or not. I've got a couple of Mullard M8100 valves supplying the P51 and I think these are a nice upgrade. I'll be searching for a couple more for the FU32 power amp over the following weeks. The P51 power lead is nothing special, it's an old power lead from a printer I once owned. I'll probably end up trying one made up from some Belden cabling offcuts and once of the silver plated plugs I have spare. It might be beneficial considering the pre-amp seems to function better with a decent PSU.
Here's a picture of the system tonight.
I swapped speaker cable. I actually used some of the legendary Peter Walker speaker cable, yep you guessed it, good old lawn mower power cable!!!!!! I salvaged 10 meters of old two core power cable from my old lawn mower, it's probably 16GA but it's copper instead of the tinned copper Duelund cabling I had in before. I think it sound better. You can see my new FREE speaker cable as the orange cable in the picture. I also have an Ankar battery PSU to try out when I can be bothered to charge the thing up.
So overall I'm having a blast with this little setup. It's great for low level listening the soundstage is very intimate and I think this system would be great for near side listening.
CCCC system and running costs. I've added the actual cost of each component even though I've had some of these sitting in the garage for years.
Mullard M8100 valves x2 £18
Little Bear P51 £16
Speaker cable - FREE
Chokes - £1 Little Bear T8 MM phonostage £19.96
Douk Audio HiFi FU32 Tube Amplifier £96.74
IC's - FREE Pre-amp power cable - FREE Power amp power cable - FREE x1 silver plated plugs £12.50
Russian RY32 valve - £12.80
TOTAL COSTS - £177.00
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Jun 28, 2020 23:59:17 GMT
One of the reasons the CCCC system came about was to get into cheap valve rolling. Mullard produce a premium valve in the guise of the M8100 which replaced the EF95 as a ruggised version. Amazingly the cost of these virtually unused valves has steadily started to increase with the onset of the Little Dot amplifiers. A valve that could be bought for a couple of pounds is now costing £8 if your lucky. The 6J1 and is Russian variants can be bought pretty cheaply from the Ukraine and China and you can even search the US of A and find variants for a few bux. My power amp uses a Chinese knock off valve called the FU-32, a direct copy of the GU-32, now you don't see many of these up for sale. I bought a Russian RY-32 valve military new old stock for a grand total of £12.80 delivered. I'm quite happy with the system so far, it does have it's limitations but I find these charming and fun. I'll post more later tonight with some pics. Pity it's not the GU-29. You could have marveled at the thought of it being used in the Russian MIG-15 Fighter. And of course it's cousin, the 6C33C, had a home in the MIG-25. Think Mr A was in the Korean Military. Lives in Canada now designing valve audio: |
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Post by jimbo on Jun 30, 2020 5:51:39 GMT
Second post of the night, blimey! I've had this little working now for two days and I've been using a myriad of bits and pieces scrounged from various cellars, lofts,garages and office drawers. I've been having lots of fun mucking around. So now it's time for a few observations. The FU-32 power amp was the cheapest amp I could find and I wanted something valve based so I could experiment with cheap valves and experience a new valve type. The FU-32 is a knock off copy of the GU-32 and boy you can tell. The supplied FU-32 valve had pins coated in very very thin nickel which flaked away. The output of the FU32 isn't massive so you'll need some efficient speakers, my Celestion Ditton 15's don't fall into that category but I can play at a reasonable level and get a decent wide soundstage which for the power output is pretty good. The Douk Audio HiFi FU32 has several speaker outputs through 2/4/8 Ohms, I went for 8 Ohms hoping this would help the amp's output. The Douk Audio HiFi FU32 has no speaker binding posts as such just several simple plastic locking posts which are tiny and mean your going to be stumped if you want to use big fat ass speaker cables. You'll struggle to get anything bigger than 16GA into those sockets, and there lies your problem. I tried Duelund 16GA and it sounded pretty good. I later swapped to something else (more later). The Douk Audio HiFi FU32 has no IEC so you've got to hard wire you power lead into the same type of plastic binding post as the speakers, again, forget using audiophile screened cable or something from Belden. My power cable was salvaged from a 5 meter run of cable which used to be attached to our old dish washer. I attached a silver plated plug and a silver plated fuse and that's about as modded as it gets for the PSU into the power amp. The really cool thing about the power amp is the variety of valves out their at cheap(ish) prices. I've already been bitten by the bug and started hunting for JAN versions of American 832A valves. I'm trying to keep the cost of this project down, a fun parameter for both my wallet and myself. I've learned in the past not to piss around and generally buy military spec valves as they are generally less microphonic and built well beyond the needs of a tiny valve amp. I hope to have fun over the next few weeks skulking around ebay.com and seeing what we can purchase from the states. I also forgot to mention the system is SILENT, no humming whatsoever. The Little Bear P51 pre-amp is slightly better constructed with very thinly gold plated RCA sockets. It's very simple audio in, audio out and a 12V power supply. I've played around with various PSU's with this little pre-amp and have found that it's responds best with 15V from a Linear PSU, yes I bought one of the cheapo Chinese Linear PSU's 2-3 years ago when you could get them for <£40 delivered. The P51 hates Walwart PSU's and I noticed hideous distortion even at low listening levels. The distortion is still around but only when you turn the thing up to full volume. I can still listen at decent levels without distortion but what do you expect from a power amp with less than 3 watts output going into an 8 Ohm speaker which needs a minimum of 10 watts !!??!! I did put a couple of ferrite chokes around the power input into the P51, I have no idea if they have helped or not. I've got a couple of Mullard M8100 valves supplying the P51 and I think these are a nice upgrade. I'll be searching for a couple more for the FU32 power amp over the following weeks. The P51 power lead is nothing special, it's an old power lead from a printer I once owned. I'll probably end up trying one made up from some Belden cabling offcuts and once of the silver plated plugs I have spare. It might be beneficial considering the pre-amp seems to function better with a decent PSU.
Here's a picture of the system tonight.
I swapped speaker cable. I actually used some of the legendary Peter Walker speaker cable, yep you guessed it, good old lawn mower power cable!!!!!! I salvaged 10 meters of old two core power cable from my old lawn mower, it's probably 16GA but it's copper instead of the tinned copper Duelund cabling I had in before. I think it sound better. You can see my new FREE speaker cable as the orange cable in the picture. I also have an Ankar battery PSU to try out when I can be bothered to charge the thing up.
So overall I'm having a blast with this little setup. It's great for low level listening the soundstage is very intimate and I think this system would be great for near side listening.
CCCC system and running costs. I've added the actual cost of each component even though I've had some of these sitting in the garage for years.
Mullard M8100 valves x2 £18
Little Bear P51 £16
Speaker cable - FREE
Chokes - £1 Little Bear T8 MM phonostage £19.96
Douk Audio HiFi FU32 Tube Amplifier £96.74
IC's - FREE Pre-amp power cable - FREE Power amp power cable - FREE x1 silver plated plugs £12.50
Russian RY32 valve - £12.80 TOTAL COSTS - £177.00
Bloody Hell Andy, its a wonder customs let that chinese amp through, it looks rather dodgy.....Kabooom! [/quote] |
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Bigman80
Grandmaster
AA Founding Member & Bigbottle Audio Creator
Posts: 16,063
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Post by Bigman80 on Jun 30, 2020 6:21:51 GMT
Second post of the night, blimey! I've had this little working now for two days and I've been using a myriad of bits and pieces scrounged from various cellars, lofts,garages and office drawers. I've been having lots of fun mucking around. So now it's time for a few observations. The FU-32 power amp was the cheapest amp I could find and I wanted something valve based so I could experiment with cheap valves and experience a new valve type. The FU-32 is a knock off copy of the GU-32 and boy you can tell. The supplied FU-32 valve had pins coated in very very thin nickel which flaked away. The output of the FU32 isn't massive so you'll need some efficient speakers, my Celestion Ditton 15's don't fall into that category but I can play at a reasonable level and get a decent wide soundstage which for the power output is pretty good. The Douk Audio HiFi FU32 has several speaker outputs through 2/4/8 Ohms, I went for 8 Ohms hoping this would help the amp's output. The Douk Audio HiFi FU32 has no speaker binding posts as such just several simple plastic locking posts which are tiny and mean your going to be stumped if you want to use big fat ass speaker cables. You'll struggle to get anything bigger than 16GA into those sockets, and there lies your problem. I tried Duelund 16GA and it sounded pretty good. I later swapped to something else (more later). The Douk Audio HiFi FU32 has no IEC so you've got to hard wire you power lead into the same type of plastic binding post as the speakers, again, forget using audiophile screened cable or something from Belden. My power cable was salvaged from a 5 meter run of cable which used to be attached to our old dish washer. I attached a silver plated plug and a silver plated fuse and that's about as modded as it gets for the PSU into the power amp. The really cool thing about the power amp is the variety of valves out their at cheap(ish) prices. I've already been bitten by the bug and started hunting for JAN versions of American 832A valves. I'm trying to keep the cost of this project down, a fun parameter for both my wallet and myself. I've learned in the past not to piss around and generally buy military spec valves as they are generally less microphonic and built well beyond the needs of a tiny valve amp. I hope to have fun over the next few weeks skulking around ebay.com and seeing what we can purchase from the states. I also forgot to mention the system is SILENT, no humming whatsoever. The Little Bear P51 pre-amp is slightly better constructed with very thinly gold plated RCA sockets. It's very simple audio in, audio out and a 12V power supply. I've played around with various PSU's with this little pre-amp and have found that it's responds best with 15V from a Linear PSU, yes I bought one of the cheapo Chinese Linear PSU's 2-3 years ago when you could get them for <£40 delivered. The P51 hates Walwart PSU's and I noticed hideous distortion even at low listening levels. The distortion is still around but only when you turn the thing up to full volume. I can still listen at decent levels without distortion but what do you expect from a power amp with less than 3 watts output going into an 8 Ohm speaker which needs a minimum of 10 watts !!??!! I did put a couple of ferrite chokes around the power input into the P51, I have no idea if they have helped or not. I've got a couple of Mullard M8100 valves supplying the P51 and I think these are a nice upgrade. I'll be searching for a couple more for the FU32 power amp over the following weeks. The P51 power lead is nothing special, it's an old power lead from a printer I once owned. I'll probably end up trying one made up from some Belden cabling offcuts and once of the silver plated plugs I have spare. It might be beneficial considering the pre-amp seems to function better with a decent PSU.
Here's a picture of the system tonight.
I swapped speaker cable. I actually used some of the legendary Peter Walker speaker cable, yep you guessed it, good old lawn mower power cable!!!!!! I salvaged 10 meters of old two core power cable from my old lawn mower, it's probably 16GA but it's copper instead of the tinned copper Duelund cabling I had in before. I think it sound better. You can see my new FREE speaker cable as the orange cable in the picture. I also have an Ankar battery PSU to try out when I can be bothered to charge the thing up.
So overall I'm having a blast with this little setup. It's great for low level listening the soundstage is very intimate and I think this system would be great for near side listening.
CCCC system and running costs. I've added the actual cost of each component even though I've had some of these sitting in the garage for years.
Mullard M8100 valves x2 £18
Little Bear P51 £16
Speaker cable - FREE
Chokes - £1 Little Bear T8 MM phonostage £19.96
Douk Audio HiFi FU32 Tube Amplifier £96.74
IC's - FREE Pre-amp power cable - FREE Power amp power cable - FREE x1 silver plated plugs £12.50
Russian RY32 valve - £12.80 TOTAL COSTS - £177.00
Bloody Hell Andy, its a wonder customs let that chinese amp through, it looks rather dodgy.....Kabooom! You've got a thing about stuff blowing up at the minute. First the Lampizator, now the Douk! lol |
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Post by rexton on Jun 30, 2020 9:44:31 GMT
They look dodgy but are actually quir well built, probably not upto oil's standard but for the cash perfectly acceptable. Nothing has blown up yet!!!!!!!
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You'll find many 6J1 variants doing the rounds on ebay, you can even go to Watford valves and find a whole section dedicated to selling upgrade 6J1 and variants. I initially decided to but x2 Mullard M8100 from Watford Valves but this would have cost me nearly £28. So, being a tight git I scoured eBay and managed to find two delivered for £18, a £10 saving. 
. So far we've spent £34 on a preamp a pair of premium military grade valves. 
. You can buy these amps cheaper but I liked the case, so probably I waste of cash. There are plenty of youtube vids on this amp and generally it can be run on anything from 9 to 24V, distortion does increase with higher voltages, so again it's looks like we are going to have some fun with playing around with PSU's. I've now got a 4 week wait for the TPA3116 but that's ok as it gives me time to hunt around office desks for old laptop PSU's and my garage for spares to cannibalise.
. Didn't find a great deal TBH. 
)
