I just finished my version of the 76/6SN7GT preamplifier, closely following the Berman schematics as published in Sound Practices #13 of 1997.
After some modifications, the preamplifier works very well with no hum or noise.
Also see the thread in the "Tubes / Valves" section: "Berman 76 preamplifier, I need some advice please".
Nice! I'm likely to build one soon too, but there are a few other projects on the bench ahead of it. I was considering it for a switchable 27/76 preamp but I hear concerns about microphonics of the 27. We'll see.
Is the nixie for input ID or something else?
PP and SE amps
Here are my latest amps, both built a number of years ago. Both are Eli Duttman designs, the "El Cheapo" Push Pull AQ5 amp and the "Dirt Cheap SE" amp (a "spud" amp using 6BM8s). Both built for amazingly short change.
I built El Cheapo maybe 6 years ago but had problems with it. I had it in service for a while and it was quite good, but I pulled it to work on and it sat on the shelf. Recently rebuilt it, worked out some issues and now it's playing beautifully. It's really way better than good now. I'm quite happy with it. Since it was an early build for me, I put switches on everything. 4/8 ohm speaker outs, switched NFB, and a heater switch to let me use 6 and 12v tubes. Top plate has been worked and re-worked, hence the holes, scratches, etc. Photo is on the bench just after final testing.
The SE has been working nicely for a few years and I never really had problems with it. It too is pretty amazing, even without considering the cost, which was really low.
I have documentation for both builds, so feel free to PM me if you're interested.
Here are my latest amps, both built a number of years ago. Both are Eli Duttman designs, the "El Cheapo" Push Pull AQ5 amp and the "Dirt Cheap SE" amp (a "spud" amp using 6BM8s). Both built for amazingly short change.
I built El Cheapo maybe 6 years ago but had problems with it. I had it in service for a while and it was quite good, but I pulled it to work on and it sat on the shelf. Recently rebuilt it, worked out some issues and now it's playing beautifully. It's really way better than good now. I'm quite happy with it. Since it was an early build for me, I put switches on everything. 4/8 ohm speaker outs, switched NFB, and a heater switch to let me use 6 and 12v tubes. Top plate has been worked and re-worked, hence the holes, scratches, etc. Photo is on the bench just after final testing.
The SE has been working nicely for a few years and I never really had problems with it. It too is pretty amazing, even without considering the cost, which was really low.
I have documentation for both builds, so feel free to PM me if you're interested.
Attachments
I just finished my version of the 76/6SN7GT preamplifier, closely following the Berman schematics as published in Sound Practices #13 of 1997.
After some modifications, the preamplifier works very well with no hum or noise.
Also see the thread in the "Tubes / Valves" section: "Berman 76 preamplifier, I need some advice please".
Where did you get the light thing showing volume?
The light is not showing the volume, it is a nixie tube next to the input selector and shows the selected input (1 to 6).
Best regards, 968driver.
Can you share how that nixie works? a schematics is much appreciated.
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Yukon Gold Spud Amp (6P15P Pentode)
http://www.diyaudio.com/forums/tubes-valves/280167-yukon-gold-spud-amp.html
http://www.diyaudio.com/forums/tubes-valves/280167-yukon-gold-spud-amp.html
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Can you share how that nixie works? a schematics is much appreciated.
sry to interrupt, this is the way I had it done on my line amp - the input selector is switching the 5V relays and they switch the anodes... psu for the nixie is like on the schematic...
hope it helps
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Can you share how that nixie works? a schematics is much appreciated.
The preamp has six line inputs, selected by relays.
A seperate deck on the input selector switches the 1, 2, 3, 4, 5 or 6 cathode of the nixie tube to ground, indicating the selected input.
The anode of the nixie is connected to the preamp +390 V supply via a
100 k resistor.
The electrolytic capacitor is needed to totally suppress a loud clicking noise when switching the input.
Best regards, 968driver.
Attachments
Thank you guys for that interesting schemas...
@968driver...what Nixie tube you use?
Works with any nixie tube, I used a Z 5600 M.
Best regards, 968driver.
https://picasaweb.google.com/109570777566485968551/Amplifiers#6214475309610943922
My work in San Diego 2015 - SE UL EL84 Funk-Werk & E80CC Tungsram gold pins. Transformers EDCOR USA.
My work in San Diego 2015 - SE UL EL84 Funk-Werk & E80CC Tungsram gold pins. Transformers EDCOR USA.
regarhttps://picasaweb.google.com/109570777566485968551/Amplifiers#6214475309610943922
My work in San Diego 2015 - SE UL EL84 Funk-Werk & E80CC Tungsram gold pins. Transformers EDCOR USA.
Very nice amplifier, I like it!
Best
ds, 968driver.
Sansui SP50 with fulranges
Actually those are a 2-way. Attached impedance plots with their XO (dotted line)
dave
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