Hello,
I'm presently unemployed and am clearing out my extra audio gear.
For sale is a fully built Neurochrome Differential Preamp. 4 stereo diff inputs, 1 stereo diff output. Tom calls this the 8x2. Included is the built input selector board. LEDs were purposely kept long in for the right enclosure which I never made. Haven't used it since about 2017 but it worked fine when put away for storage, so last I knew it worked perfectly.
I've been soldering professionally for 30 years so please have confidence that the build quality is good.
$250 plus shipping from 63025.
I'm presently unemployed and am clearing out my extra audio gear.
For sale is a fully built Neurochrome Differential Preamp. 4 stereo diff inputs, 1 stereo diff output. Tom calls this the 8x2. Included is the built input selector board. LEDs were purposely kept long in for the right enclosure which I never made. Haven't used it since about 2017 but it worked fine when put away for storage, so last I knew it worked perfectly.
I've been soldering professionally for 30 years so please have confidence that the build quality is good.
$250 plus shipping from 63025.
Codewriter I do wish to buy the preamp. I'm not sure why the message isn't working. My email dunkleya@bell.net.
Just a question regarding why the pot is a 2-gang only for a differential pre-amp?
Wish you luck for your work situation!
Wish you luck for your work situation!
Likely used as a variable resistor across the lines, with series resistors in each line.
A variable H-pad.
https://realoldiesradio.com/?p=212
Because the DIFF PRE runs single-ended on the board. If the board is competently done there's no technical need for a 4-gang pot. That's not to say someone couldn't invent a marketing need, though... 😉
Tom
I agree. I have heard some say that a preamp that is totally differential all the way through has some audible advantage, but I cannot see how---I think it is marketing audiophool nonsense.
OK, Mr. Designer----what ICs did you use in your preamp?
OK, Mr. Designer----what ICs did you use in your preamp?
This clearly means that the amp is not differential but has only differential inputs and outputs.
Thanks for clarification, Tom.
So, people like Nelson Pass and others do nonsense, lol.
But to give you an idea about benefits, signal doesn‘t touch ground (*) in a differential (also called balanced) design and you have double the voltage swing at the output and increased slew rate.
(*) A loudspeaker do not have ground, it only has hot and cold. Best is to take those from a differential amp. Of course you can connect minus to ground and safe half of the cost with a single ended amp.
Same with balanced vs. single ended headphones (where both channel cold is jointly connected to ground in order to keep cost down; and that‘s the only benefit)…
Having only the IO differential on a single ended amp, has an advantage only on the cabling length and signal transmission, which with short cable runs in a typical home environment is pretty much 0, but adds more electronics (thus noise and distortion) to the signal path.
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I like the marketing term „differential pre running single ended“, thats award winning.
The proper technical description would have been single ended amp featuring balanced IO. Nice one 👍🏻
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Proper according to who?
The DIFF PRE had fully balanced inputs, fully balanced outputs, CMRR over 95 dB, multi-tone IMD exceeding 140 dBr, and mains hum below what my APx525 could measure. You want to argue marketing babble? I'd rather talk about performance. That's what I deliver. Performance.
Tom
The DIFF PRE had fully balanced inputs, fully balanced outputs, CMRR over 95 dB, multi-tone IMD exceeding 140 dBr, and mains hum below what my APx525 could measure. You want to argue marketing babble? I'd rather talk about performance. That's what I deliver. Performance.
Tom
Yes, marketing. Calling the amp differential is simpy technically wrong. I was looking at it because it was called „differential amp“ only to find out it uses a 2 gang pot. Don‘t want to argue about your performance as I have not seen, listened to and measured it, but it cleary is a single ended amp with differential inputs and outputs only. That‘s what it is, period.
PS: proper according to engineering terms and not to your marketing agenda.
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Oh, I think I know proper engineering terminology.
Tom
Tom