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Post by alit on Sept 8, 2023 18:39:11 GMT
I've been using a Modulus 86 for a while now, having acquired the "Cadbury" amp built by Alan with dual mono LPS some time ago. I've been very happy with it, it brought to an end many years of playing with various amps both valve and SS. It's the closest thing I've heard at home to a straight wire with gain and have not had any urge for change. Given my speakers are approx 91-92dB and an easy load, it goes as loud as I could wish.
Saying that, it was always the intention to go for a 686, just in case I'm missing something with the lower powered version. :-)
To that end I've been talking to Joe Henry about some monos. Working away a lot as I do, I don't have the time to build them myself so thought I'd see what he would come up with. Talked to him about using Qspeed diodes and he mentioned he has some boards for active bridges, so decided to go with them.
So what I have so far is- Monoblocks, 500va toroids (Joe uses Virgotronix), active bridges, 4 x 47,000uF per mono.
Anyone have any suggestions for anything else?
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Bigman80
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Post by Bigman80 on Sept 8, 2023 19:26:35 GMT
I've been using a Modulus 86 for a while now, having acquired the "Cadbury" amp built by Alan with dual mono LPS some time ago. I've been very happy with it, it brought to an end many years of playing with various amps both valve and SS. It's the closest thing I've heard at home to a straight wire with gain and have not had any urge for change. Given my speakers are approx 91-92dB and an easy load, it goes as loud as I could wish. Saying that, it was always the intention to go for a 686, just in case I'm missing something with the lower powered version. :-) To that end I've been talking to Joe Henry about some monos. Working away a lot as I do, I don't have the time to build them myself so thought I'd see what he would come up with. Talked to him about using Qspeed diodes and he mentioned he has some boards for active bridges, so decided to go with them. So what I have so far is- Monoblocks, 500va toroids (Joe uses Virgotronix), active bridges, 4 x 47,000uF per mono. Anyone have any suggestions for anything else? Just my 2p worth: First off, those traffos need to be 240v or they'll end up buzzing. I'd go for Traffos from Toroidy and specifically spec them at 240v. They don't cost much more than off the shelf varieties. Secondly, you want to take the connectors out of the PCB. Those molex type connectors are brass, and we all know my feelings on brass in the audio chain...and yes, even on a power amp. Also bear in mind that you can have too much of a good thing, and nearly 200,000uf in each mono could certainly qualify. JH may want to just run the calculator over that before committing. Thirdly, Qspeed diodes why? Genuinely asking why over a GBX XXX package for Instance |
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Post by alit on Sept 8, 2023 19:37:03 GMT
For the quietest supply possible. As far as I know Qspeed are the quietest available and an active bridge will be quieter still.
I assume the toroids will be 240 primary but I’ll check with Joe.
I can easily try less capacitance myself, I have asked why, but given he’s built quite a few, I guess he should have a good handle on the circuit.
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Post by ijrussell on Sept 8, 2023 19:45:49 GMT
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Post by alit on Sept 8, 2023 20:14:13 GMT
Pic of the active boards-  |
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Post by alit on Sept 8, 2023 20:17:28 GMT
Looks like he used the same level of capacitance in yours?
EDIT. Ah I see, a little less, but not much.
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Bigman80
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Post by Bigman80 on Sept 8, 2023 21:17:21 GMT
Looks like he used the same level of capacitance in yours? EDIT. Ah I see, a little less, but not much. The traffos are labelled for 230v in Ian's build. |
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Post by ijrussell on Sept 8, 2023 21:32:02 GMT
Looks like he used the same level of capacitance in yours? EDIT. Ah I see, a little less, but not much. The traffos are labelled for 230v in Ian's build. They don't hum at all. . |
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Post by ijrussell on Sept 8, 2023 21:34:43 GMT
Looks like he used the same level of capacitance in yours? EDIT. Ah I see, a little less, but not much. I believe this level of capacitance is what Rolls Royce describe as "adequate". Your proposed level is just showing off! . |
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Post by alit on Sept 8, 2023 21:35:04 GMT
I will make sure they are 240. The mains here hovers around 250…
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Post by alit on Sept 8, 2023 21:36:26 GMT
Looks like he used the same level of capacitance in yours? EDIT. Ah I see, a little less, but not much. I believe this level of capacitance is what Rolls Royce describe as "adequate". Your proposed level is just showing off! . LOL, definitely adequate. I suspect he’s using them as he already has them. It’s a common value for a power supply cap. |
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Post by electronumpty on Sept 8, 2023 22:17:46 GMT
Pic of the active boards- I have the same boards for my Wolverine project , not cheap to populate mind. But no need for snubbers to stop the tx ringing and less voltage drop. |
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Bigman80
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Post by Bigman80 on Sept 8, 2023 22:38:59 GMT
Pic of the active boards- I have the same boards for my Wolverine project , not cheap to populate mind. But no need for snubbers to stop the tx ringing and less voltage drop. What's the BOM look like? |
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Post by alit on Sept 8, 2023 22:42:02 GMT
Pic of the active boards- I have the same boards for my Wolverine project , not cheap to populate mind. But no need for snubbers to stop the tx ringing and less voltage drop. Yeah extra cost but hopefully worth it. |
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Post by electronumpty on Sept 8, 2023 22:58:59 GMT
I have the same boards for my Wolverine project , not cheap to populate mind. But no need for snubbers to stop the tx ringing and less voltage drop. What's the BOM look like? I post it tomorrow, not too much in it, the control chip is the expensive bit. |
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Post by misterc on Sept 9, 2023 8:01:13 GMT
I would expect if you quality SiC or GaN FET's this will improve matters no end on this $6 board design, again ultra low impedence is the key goal here why are there wires being used here I'm genuinelly curious? the obvious design idea is not present here, not sure why??
Would also suggest a quality dc blocking circuit as well here.
Oddly enough in the last 8 weeks the mains voltage has dropped from 246+ to a rock steady 230-232 max quite surpised. All Solution owners should be really pleased now!!
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Post by alit on Sept 9, 2023 12:18:57 GMT
You referring to the active boards Tony? Which wiring do you mean?
Blocker is a good shout, Nick does a good one, I’ll get a pair from him.
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Bigman80
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Post by Bigman80 on Sept 9, 2023 12:40:27 GMT
You referring to the active boards Tony? Which wiring do you mean? Blocker is a good shout, Nick does a good one, I’ll get a pair from him. I believe T is talking about the JH build pics? |
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Post by misterc on Sept 9, 2023 12:50:01 GMT
Hi Ali
I was referring to the FET style set up’s with a diode controller i/c, these have zero forward voltage ability but with much quieter switching noise. I see no total capacitance rating listed on these, personally I would be looking @less than 65nC.
Its very weird you guys doing the exact same thing I'v e been working on for the last week on and off, I have been experimenting with a new wide band gap configurations with DC, but to really get this quiet at the sort of currents I require for the new amps is at least 6 layers,*the four I tested yesterday was layout out spot on but my copper pour and pre preg wasn't up to the job.
Have to wait until next Friday for the new prototype boards, in the meantime I have been refining the old skool method and it proving pleasing results. I literally have just ordered two dozen new diodes and some very nice board mount hardware. Please don't complain about BOM costs until you have refined the design just the diodes/board mount connectors & heat sinks were just under 500, that is enough for three test just set ups! So far with the other method it’s been somewhat higher!
With regard to the wiring from the rectification board to the caps, think about all that extra inductance just playing silly beggars with the impedance. I always like to give pointers Ali, but think about this ideally how to remove all that un necessary loading and space in an amplifier.
There are a few amp designers that have worked it out now apart from ourselves, but think about how best to use the components you have and maybe to look at redesigning those parts save space and improve performance.
Sorry I'm not going to give it away here, you guys are pretty switched on to come up with a solution, maybe when the temptrature has calmed down a bit lol
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Post by misterc on Sept 9, 2023 13:02:54 GMT
You referring to the active boards Tony? Which wiring do you mean? Blocker is a good shout, Nick does a good one, I’ll get a pair from him. I believe T is talking about the JH build pics? The Wiring from these to the main caps chaps
This was the image I was reffering to Ali sorry. This is a neat job genuinelly with off the shelf parts, very tidy and like the vertically mounted Tx's
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Post by alit on Sept 9, 2023 13:06:08 GMT
I could mount the boards on top of the caps, keep the wire runs as short as possible?
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Bigman80
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Post by Bigman80 on Sept 9, 2023 13:11:45 GMT
I could mount the boards on top of the caps, keep the wire runs as short as possible? That's the idea 👍 |
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Post by misterc on Sept 9, 2023 13:29:23 GMT
This is an old design now Ali, however just a scaled up version of this.
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Post by alit on Sept 9, 2023 15:49:00 GMT
Even better, no leads at all.
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Post by electronumpty on Sept 10, 2023 20:27:42 GMT
What's the BOM look like? Here you go 1 LT4320HN8-1# PBF-ND LT4320HN8-1#PBF IC OR CTRLR BRIDGE RECT 8DIP 1 LT4320IMSE# PBF-ND LT4320IMSE#PBF IC OR CTRLR BRIDGE RECT 12MSOP 1 ED3013-ND SA083040 CONN IC DIP SOCKET 8POS GOLD 1 A129861CT-ND CRGCQ1210F150R CRGCQ 1210 150R 1% 1 399-11578-1-ND C1210C103J2GACAUTO CAP CER 10000PF 200V NP0 1210 1 720-2063-1-ND VJ1210Y154KXCAT CAP CER 0.15UF 200V X7R 1210 1 445-9276-1-ND CGJ6M3X7R2D154K200AA CAP CER 0.15UF 200V X7R 1210 1 565-4013-ND EKYB101ELL101MJ20S CAP ALUM 100UF 20% 100V RADIAL 2 1928-1656-ND MKS2D031001A00MSSD CAP FILM 0.1UF 20% 100VDC RAD 1 C503B-BCN-CV0Z0461-ND C503B-BCN-CV0Z0461 LED BLUE CLEAR 5MM ROUND T/H 1 P15KW-3BK-ND ERG-3SJ153 RES 15K OHM 3W 5% AXIAL 4 A100452CT-ND 1217861-1 CONN QC TAB 0.250 SOLDER 4 296-37286-5-ND CSD19501KCS MOSFET N-CH 80V 100A TO220-3 There are other options for the Mosfets |
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Post by alit on Sept 11, 2023 17:49:38 GMT
What's the total cost?
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Post by electronumpty on Sept 11, 2023 19:37:39 GMT
Works out about £20 a board. The chip is about half that. |
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Bigman80
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Post by Bigman80 on Sept 11, 2023 19:50:05 GMT
Works out about £20 a board. The chip is about half that. That's not bad. |
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Post by electronumpty on Sept 11, 2023 21:08:53 GMT
Works out about £20 a board. The chip is about half that. That's not bad. No, but if you're doing 2 per rail it does add up compared to bridge diodes. As always depends on budget etc. |
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Post by alit on Sept 12, 2023 12:43:57 GMT
Thanks.
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