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Post by Deleted on May 12, 2020 16:41:01 GMT
Yeah probably just my misunderstanding of the situation as I've dumped about £450 in to this so far so didn't want to be thinking fundamental issues were being unearthed.... Alan and I fettle absolutely everything that we either buy or build. Look at his brand new Paradise, it's already stripped down and being rebuilt!!!! He only had it 1 day! We've explored improvements to absolutely everything, including a Tron Convergence. The philosophy is that we never rule anything out unless we've tried it and if there is a gain to be had by pairing up Jfets, then we will explore it, implement it and release the mod! Even the mod will be free if you build it yourself. Nothing wrong with exploring improvements. As previously mentioned, everything can be improved but where hifi is concerned it's seldom as straightforwards as many enthusiasts might think. Usually altering one part of a circuit has knock on effects somewhere else so in many cases, the more accurate way of looking at it, is that there are real improvements to specified outputs such as accuracy, S/N, efficiency and so on and these need to be measured and those measurements shown to be said to be an "improvement". There are changes which make the sound different, more to personal tastes and these it can be argued are not improvements, they're changes. In speaker-land, many people think that tweaking their speakers by altering some things like tuning or internal stuffing or even crossover components is "improving" things to their ears. Whilst that might be perfectly true and valid, technically they may have actually ruined the design and I do see a lot of "improvements" on speakers, some of which have resulted in large bills where voicecoil formers have been rounded and ruined for example where tuning has been messed with (get vented tuning wrong by lowering it too much for example and the voicecoil can smack against the pole piece and wreck drive unit). Philosophical stuff improvements. Can be technical too! |
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Post by Deleted on May 12, 2020 16:42:37 GMT
That was quick! By each output Alan, presumably you mean to wire the 9.5v secondaries from the transformer in series with the transformer and the input of this board then the board outputs to the bB3 inputs? So the 165V 0.1A is left as-is.. Oh I can be quick if I want to, lol. I had the boards on order a few days ago actually. The board connects to the signal outputs of the board, not the transformer connections. It acts to short circuit the signal outputs, so preventing any pops or DC. Once the 30 second delay is over all that is connected across the outputs is an open relay contact, so no affect to the sound. Thanks Alan. |
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Post by antonio on May 12, 2020 17:18:40 GMT
Great write up Paul, more than likely it needs a bit more time. We're in the process of assessing a new ( 2nd hand ) speaker cable, only came today, and a quick A-B was a touch disappointing although we are now just listening and hearing new things all the time. Just out of curiosity, if someone wanted a BB3 made up how much would it cost ( just a rough idea is good enough )?
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Post by Bigman80 on May 12, 2020 17:24:45 GMT
Great write up Paul, more than likely it needs a bit more time. We're in the process of assessing a new ( 2nd hand ) speaker cable, only came today, and a quick A-B was a touch disappointing although we are now just listening and hearing new things all the time. Just out of curiosity, if someone wanted a BB3 made up how much would it cost ( just a rough idea is good enough )? Diy: Under £400 MAX. It's possible to do it for around £300 Made for you by me, £800 That's a 2 box build, EI Transformer, matched Fets...no matter how many we use lol Matched per channel, using 0.1% resistors and 1% caps. |
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Post by antonio on May 12, 2020 17:29:39 GMT
Thanks Oli, just for comparison with the Tron Convergence, 20% cheaper.
Edit: Just looked again, and the Tron price has risen to £1300 and £1500 for an upgraded version.
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Post by Bigman80 on May 12, 2020 17:37:40 GMT
Thanks Oli, just for comparison with the Tron Convergence, 20% cheaper. Yes. And as a developing phonostage, any mods we come up with will be backwards compatible, so if we find an upgrade, you can have it done for the cost of parts. Dont get that with the TRON do ya lol  |
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Post by Bigman80 on May 12, 2020 17:38:54 GMT
Thanks Oli, just for comparison with the Tron Convergence, 20% cheaper. Edit: Just looked again, and the Tron price has risen to £1300 and £1500 for an upgraded version. Oh I am even happier.....its nearly 50% cheaper!!!!! And for reference: Tron: Frequency response:- 20Hz – 20KHz +/- 1dB BB3: -20Hz – 20KHz +/- 0.3 to 0.7dB This is depending on how careful you are with matching the resistors and caps. Want to upgrade the BB3? Add £150 for Clarity Cap output caps and an Ultra low noise regulator to replace the 7805 and CMC Copper RCA sockets and Copper loading plugs. |
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Post by Deleted on May 12, 2020 17:56:22 GMT
One thing I forgot to organise was my loading plugs. Is there any default loading in both the MM/MC setting?
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Post by Deleted on May 12, 2020 18:04:34 GMT
Diy: Under £400 MAX. It's possible to do it for around £300 Made for you by me, £800 That's a 2 box build, EI Transformer, matched Fets...no matter how many we use lol Matched per channel, using 0.1% resistors and 1% caps. I'm at about £450 with no valves yet although I've probably put £100 more into my case than is needed so call it £350 with no valves. |
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Post by Bigman80 on May 12, 2020 18:04:44 GMT
One thing I forgot to organise was my loading plugs. Is there any default loading in both the MM/MC setting? In MC, If you use 110R then that will give you 100R |
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Post by Deleted on May 12, 2020 18:27:58 GMT
Ok thanks so about 1k default
what capacitance is there for mm too?
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Post by Bigman80 on May 12, 2020 18:50:26 GMT
Ok thanks so about 1k default what capacitance is there for mm too? 150pf |
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Post by Deleted on May 12, 2020 19:06:42 GMT
Thanks Oli, just for comparison with the Tron Convergence, 20% cheaper. Edit: Just looked again, and the Tron price has risen to £1300 and £1500 for an upgraded version. Oh I am even happier.....its nearly 50% cheaper!!!!! And for reference: Tron: Frequency response:- 20Hz – 20KHz +/- 1dB BB3: -20Hz – 20KHz +/- 0.3 to 0.7dB This is depending on how careful you are with matching the resistors and caps. Want to upgrade the BB3? Add £150 for Clarity Cap output caps and an Ultra low noise regulator to replace the 7805 and CMC Copper RCA sockets and Copper loading plugs. Is that measured out of interest? |
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Post by Bigman80 on May 12, 2020 19:10:28 GMT
Oh I am even happier.....its nearly 50% cheaper!!!!! And for reference: Tron: Frequency response:- 20Hz – 20KHz +/- 1dB BB3: -20Hz – 20KHz +/- 0.3 to 0.7dB This is depending on how careful you are with matching the resistors and caps. Want to upgrade the BB3? Add £150 for Clarity Cap output caps and an Ultra low noise regulator to replace the 7805 and CMC Copper RCA sockets and Copper loading plugs. Is that measured out of interest? Yes, independently by craigtone USA |
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Post by Deleted on May 12, 2020 19:12:23 GMT
Thanks Oli, just for comparison with the Tron Convergence, 20% cheaper. Yes. And as a developing phonostage, any mods we come up with will be backwards compatible, so if we find an upgrade, you can have it done for the cost of parts. Dont get that with the TRON do ya lol Actually Oli that is not correct and I would most humbly suggest that perhaps you need to tread a little more gingerly when making such claims. Tron improvements ARE backwards compatible, can be retrofitted and any issues are sorted free of charge, no quibbles, ever. Graham will upgrade parts anyone's kit for the cost of parts and a reasonable sum for labour but if there is ever a circuit issue requiring an upgrade that is done free. He puts so much time and cash into development I have yet to hear of any of his products needing these tweaks to meet expected or claimed performance and I do think you're being rather unfair here if honest. Just saying like.  |
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Post by Bigman80 on May 12, 2020 19:25:36 GMT
Yes. And as a developing phonostage, any mods we come up with will be backwards compatible, so if we find an upgrade, you can have it done for the cost of parts. Dont get that with the TRON do ya lol Actually Oli that is not correct and I would most humbly suggest that perhaps you need to tread a little more gingerly when making such claims. Tron improvements ARE backwards compatible, can be retrofitted and any issues are sorted free of charge, no quibbles, ever. Graham will upgrade parts anyone's kit for the cost of parts and a reasonable sum for labour but if there is ever a circuit issue requiring an upgrade that is done free. He puts so much time and cash into development I have yet to hear of any of his products needing these tweaks to meet expected or claimed performance and I do think you're being rather unfair here if honest. Just saying like. Well, I wasnt intentionally being unfair. What are the mods/upgrades, he retrofits or add to the Tron? |
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Post by electronumpty on May 12, 2020 19:29:42 GMT
Never heard any Tron stuff but I really like the styling of the brand. Looks very well thought out imo.
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Post by Bigman80 on May 12, 2020 20:12:01 GMT
Yes. And as a developing phonostage, any mods we come up with will be backwards compatible, so if we find an upgrade, you can have it done for the cost of parts. Dont get that with the TRON do ya lol Actually Oli that is not correct and I would most humbly suggest that perhaps you need to tread a little more gingerly when making such claims. Tron improvements ARE backwards compatible, can be retrofitted and any issues are sorted free of charge, no quibbles, ever. Graham will upgrade parts anyone's kit for the cost of parts and a reasonable sum for labour but if there is ever a circuit issue requiring an upgrade that is done free. He puts so much time and cash into development I have yet to hear of any of his products needing these tweaks to meet expected or claimed performance and I do think you're being rather unfair here if honest. Just saying like. Just reread your post Paul, i was walking the dogs originally. My : "You dont get that with Tron" was very tongue in cheek and I was just being a bit mischievous. No harm meant. I would be interested to knownwhat sets the standard apart from the Signature one though. I'll have a browse of the website. |
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Post by Deleted on May 12, 2020 20:26:02 GMT
Actually Oli that is not correct and I would most humbly suggest that perhaps you need to tread a little more gingerly when making such claims. Tron improvements ARE backwards compatible, can be retrofitted and any issues are sorted free of charge, no quibbles, ever. Graham will upgrade parts anyone's kit for the cost of parts and a reasonable sum for labour but if there is ever a circuit issue requiring an upgrade that is done free. He puts so much time and cash into development I have yet to hear of any of his products needing these tweaks to meet expected or claimed performance and I do think you're being rather unfair here if honest. Just saying like. Well, I wasnt intentionally being unfair. What are the mods/upgrades, he retrofits or add to the Tron? There's a few stages that he offers across the range so that his Reference or Signature range for example are backwards compatible with the entry level. From power supply upgrades through to parts upgrading, improving tolerance and further reductions in noise to name a few. There's a huge difference for example in the preamps between the Reference and the entry level models. He's also designed those so you can chose to add on things like channel balance or not, or have a phono input or go for the standard line level versions. His Seven phono is out of my reach now that all my budget (at the time) went into the not inconsiderable sum needed for the Seven Reference model. In that I have some beautiful work...absolute works of art to look at and dripping with top class products from the individually choked channels (as well as the main PSU choke) to the top notch volume pot he fitted for me. It is without a shadow of a doubt one of the finest and quietest line level preamps I've ever heard. I had a listen to a modwright a few years back and imho the TRON reference bettered it. I wouldn't sink cash into something like this unless there was good reason. The only job I had to do was to load the inputs slightly of the Series 5 Radford I use as the TRON had a little too much gain. It's also because I had faith in you and Alan and in your enthusiasm which is infectious that I decided the BB3 would not only be a fun project but would also result in a great finished article. |
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Post by Deleted on May 12, 2020 20:38:16 GMT
Actually Oli that is not correct and I would most humbly suggest that perhaps you need to tread a little more gingerly when making such claims. Tron improvements ARE backwards compatible, can be retrofitted and any issues are sorted free of charge, no quibbles, ever. Graham will upgrade parts anyone's kit for the cost of parts and a reasonable sum for labour but if there is ever a circuit issue requiring an upgrade that is done free. He puts so much time and cash into development I have yet to hear of any of his products needing these tweaks to meet expected or claimed performance and I do think you're being rather unfair here if honest. Just saying like. Just reread your post Paul, i was walking the dogs originally. My : "You dont get that with Tron" was very tongue in cheek and I was just being a bit mischievous. No harm meant. I would be interested to knownwhat sets the standard apart from the Signature one though. I'll have a browse of the website. No worries Oli and hopefully I have explained above the differences. The real mainstream hifi world in the UK is no longer is represented in mainstream audio but has gone underground and lays, mostly, with smaller companies and one man bands producing some truly superb and well engineered pieces of kit. I got to thinking about this recently and wondered why that was. I thought back on my own experiences of the past 5 or 6 years where I have now been called and asked to join several companies, two household names, but i turned all down. Why? because although I hold them all in respect, ultimately their output has to be compromised to account for the market in the Far East, for distribution and retail profit and to make manufacture economic and in some cases cut one corner too many. I may only produce a small handful of loudspeakers each year but I try not to any corners and put 100% into the final product, often swallowing what profit might have gone to a distributor in the process to get things to a standard, because I want the customer to have something they'll enjoy for life. To date, not one of my own speakers has been moved on in the 2nd hand market. All have remained with the owners so somewhere, something has gone right. That for me is the difference and why I love what I do. I'm sure that you and Alan have a similar outlook. Therein lies the point. I think that rather than compete against other niche producers and perhaps target their products, perhaps unintentionally putting out the wrong signals, there's so few of us left we really need to respect and look out for each other. We all have slightly different markets which is why we can co-exist harmoniously so comparisons are sometimes a little misleading or perhaps not really comparable as one company may make different products aimed at a slightly different market, be that overseas, or a different demographic or simply to those who attempt no DIY and wish to be cosseted and looked after so that they have complete confidence in the standards of the finished product. I think that Graham is very much of the latter persuasion and a more lovely bloke, seriously, you could not meet. Hope sharing those thoughts helps explain where i'm coming from  |
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Post by Bigman80 on May 12, 2020 20:40:59 GMT
Just reread your post Paul, i was walking the dogs originally. My : "You dont get that with Tron" was very tongue in cheek and I was just being a bit mischievous. No harm meant. I would be interested to knownwhat sets the standard apart from the Signature one though. I'll have a browse of the website. No worries Oli and hopefully I have explained above the differences. The real mainstream hifi world in the UK is no longer is represented in mainstream audio but has gone underground and lays, mostly, with smaller companies and one man bands producing some truly superb and well engineered pieces of kit. I got to thinking about this recently and wondered why that was. I thought back on my own experiences of the past 5 or 6 years where I have now been called and asked to join several companies, two household names, but i turned all down. Why? because although I hold them all in respect, ultimately their output has to be compromised to account for the market in the Far East, for distribution and retail profit and to make manufacture economic and in some cases cut one corner too many. I may only produce a small handful of loudspeakers each year but I try not to any corners and put 100% into the final product, often swallowing what profit might have gone to a distributor in the process to get things to a standard, because I want the customer to have something they'll enjoy for life. To date, not one of my own speakers has been moved on in the 2nd hand market. All have remained with the owners so somewhere, something has gone right. That for me is the difference and why I love what I do. I'm sure that you and Alan have a similar outlook. Therein lies the point. I think that rather than compete against other niche producers and perhaps target their products, perhaps unintentionally putting out the wrong signals, there's so few of us left we really need to respect and look out for each other. We all have slightly different markets which is why we can co-exist harmoniously so comparisons are sometimes a little misleading or perhaps not really comparable as one company may make different products aimed at a slightly different market, be that overseas, or a different demographic or simply to those who attempt no DIY and wish to be cosseted and looked after so that they have complete confidence in the standards of the finished product. I think that Graham is very much of the latter persuasion and a more lovely bloke, seriously, you could not meet. Hope sharing those thoughts helps explain where i'm coming from I like the sentiment in that Paul. I'm in. |
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Post by Deleted on May 12, 2020 21:09:00 GMT
Ok thanks so about 1k default what capacitance is there for mm too? 150pf Great thank you. |
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Post by Deleted on May 13, 2020 7:42:13 GMT
Scotty,
generally with MM, the less the capacitance the better even if a manufacturer of cartridges says "it needs 300pF" because adding capacitance doe two things: It pulls the resonant spike further down into the audible spectrum, sometimes making the cart sound "brighter" or harsh and secondly it rolls off the top end earlier. Generally speaking (as it is not 100% always the case) the less the better.
Just as a guide to you and others:
Tonearm wiring (measured) to output, be that captive or RCA socksts = 30pF to 40pF;
Per metre of 6mm o/a coax (don't use twin core overall shield for MM, only for MC) based on average signal core of 0.2 to 0.4mm diameter = 75pF IF PE is the dielectric;
RCA sockets (per socket) = 3 to 4pF
RCA connectors = 5pF average
For a standard 1.2m tonearm cable (taken from the old British industry standard of 4ft), total capacitance up to the phonostage is likely to be about 130 to 145pF.
It isn't by chance that the industry standard (not a real standard) is 150pF as if you look at MM cartridges of say 1970's to the "Noughties" the average load capacitance they claim was needed (based on the self inductance of the cartridges) was around 250 to 300pF.
These days, carts have changed a bit and I would argue that capacitance should be kept as low as is possible for best results. I have not added any additional load capacitance to mine and use it just as it is. Stages also need that to be seen as the direct load capacitance by the cartridge at the input. Further down the circuit doesn't really reflect as true direct load at input, so it would be helpful, somehow if in operation, the actual input load capacitance could be tested (is this possible at all Alan?). The lower, the better!
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Post by Deleted on May 13, 2020 8:07:11 GMT
Thanks much appreciated. At the moment, with my AT740 on my LP12, I have the capacitance wound right down on my phono stage (15pF) and I'm using Blue Jeans cables which are 12pF per foot. Add that to the tonearm cable etc and I'm probably in the 100pF region in total and that's about as low as I can get it with what I have here. Sounds ok though and it's the reason I was asking about the default loading so I know what to add to my loading plugs to get me back to this ballpark for my MM cartridge.
For MC I'm using an SPU which is seeing roughly 10 ohms (I think) with my FRT-5 so again, knowing the default, I can parallel resistors to get me to this ballpark.
Well, at least I know what I'm starting with so can experiment accordingly.
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Post by firebottle on May 13, 2020 9:27:08 GMT
The BB inputs have a couple of 100pF capacitors fitted, C1L & R.
With the approx 50pF Miller capacitance from valve V1 this gives 150pF. You could miss out or fit a lower value for C1 to adjust
I did measure the input capacitance without C1 and it was around 48pF.
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Post by Deleted on May 13, 2020 9:28:45 GMT
Great, good to know thanks
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Post by Deleted on May 13, 2020 10:04:19 GMT
Thanks much appreciated. At the moment, with my AT740 on my LP12, I have the capacitance wound right down on my phono stage (15pF) and I'm using Blue Jeans cables which are 12pF per foot. Add that to the tonearm cable etc and I'm probably in the 100pF region in total and that's about as low as I can get it with what I have here. Sounds ok though and it's the reason I was asking about the default loading so I know what to add to my loading plugs to get me back to this ballpark for my MM cartridge. For MC I'm using an SPU which is seeing roughly 10 ohms (I think) with my FRT-5 so again, knowing the default, I can parallel resistors to get me to this ballpark. Well, at least I know what I'm starting with so can experiment accordingly. Personally, I'd keep the input loading for MM as low as possible and listen before adding anything, and listen for balance in the upper registers, Odds on evens I'd guess adding say even 100pF might bring a spike into the upper mids. The AT470 is recommended with between 100 and 200pF so you're there already without adding any more. I'm in the same boat with my MP-500 which likes to see 100pF (impossibility!) Loading on MC's, IF the step up device or SUT have been correctly designed, is only there to protect the windings from over-current, so a sort of rule of thumb applies: Multiply cartridge self impedance by ten as the minimum load impedance (in your case, the self impedance of the VM740 being an MM is 2,700 Ohms o the standard 47K loading is sufficient for that one). |
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Post by Deleted on May 13, 2020 10:15:45 GMT
Yep 100% agree, when I speak of adding I mean in parallel to bring the capacitance down as required.
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Post by Deleted on May 13, 2020 10:17:00 GMT
The BB inputs have a couple of 100pF capacitors fitted, C1L & R. With the approx 50pF Miller capacitance from valve V1 this gives 150pF. You could miss out or fit a lower value for C1 to adjust I did measure the input capacitance without C1 and it was around 48pF. Thanks Alan. That's great. |
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Post by Deleted on Jun 4, 2020 18:57:09 GMT
Update, better late than never. Been crook so under the radar for a while.
Changes to mine now include a superb V2 valve, the Tongsol 12ax7803s short plate gold pin. Low to non-existant microphonics and superb mid clarity. Stunning valve. Highly recommended.
Waiting for a pair of POCC88 Teles to arrive (5 weeks so far) meantime a Pinnacle PCC88 did the trick in V1 and killed the microphoncs dead.
Contact suppressor fitted across transformer secondary rails to prevent arcing across switch on switch off and, thanks to Alan, the soft start/switchoff PCB is now fitted and wired in which has taken care of the switch off causing a large voltage spike to drop across the rails.
Just playing with earthing arrangements for MC to eliminate picking up Radio 2! I've narrowed down the culprit which was a commoned earth between cart signal return and tonearm. These need splitting out with the tonearm going to chassis.
Decals a work in progress. Will upload photos when done.
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