Well, yes @jean-paul, this preamp needs an amplifier with low gain. I happen to have received an amplifier with only 16dB of gain just a day ago, and will be trying it with this preamp soon 😉
Ah the marrying of non standardized stuff. About the same as solving an error with an error but that’s OK 🙂 Good luck, I hope it will work out.
Funny is that standardized stuff often is misinterpreted/misunderstood/wrongly applied in non standardized chains. Still the matching is fun to do but it takes time and patience. Burnt my fingers a few times in such Sackgasse situations. Lessons learned.
Funny is that standardized stuff often is misinterpreted/misunderstood/wrongly applied in non standardized chains. Still the matching is fun to do but it takes time and patience. Burnt my fingers a few times in such Sackgasse situations. Lessons learned.
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Remove the 'lytics from pins 3 & 8 of the input tube.Can this be done without a major overhaul and just some parts swapping?
This is an existing circuit on a PCB, and I don't want to totally reengineer it, hopefully just swap some part values to reduce the overall gain.
yaquin 845 pre schem by Barry, on Flickr
Thank you
Then it's wasn't a Baxandall circuit. It needs to be fed from a low source impedance, and it doesn't contain any voltage dividers.
ejp,
Look at figure 8.1 (deep inside the document) That is what I built x2. One in a preamp and the other in a small computer speaker 6V6 integrated amp. In both cases I needed to add a 12AX7 gain stage in front of the illustrated tone circuit. If I fed my nominal 2v source signal after the tone control, it drove the amps to full power. But not with this circuit in the path.
What do you think?
https://www.angelfire.com/electronic/funwithtubes/Amp-Tone-A.html
Look at figure 8.1 (deep inside the document) That is what I built x2. One in a preamp and the other in a small computer speaker 6V6 integrated amp. In both cases I needed to add a 12AX7 gain stage in front of the illustrated tone circuit. If I fed my nominal 2v source signal after the tone control, it drove the amps to full power. But not with this circuit in the path.
What do you think?
https://www.angelfire.com/electronic/funwithtubes/Amp-Tone-A.html
I don't see any 220k source resistance, or any significantly lossy voltage dividers. The text specifically warns against high source impedance.
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I was recalling from memory, the 220k wasn't where I thought. Anyway I don;t think a CD player is high impedance. and I used linear pots as specified. Yes, it need more analysis but I have moved on tp other projects,
So, I hooked the pre up to an Orchard Audio Starkrimson Ultra, was a really nice pairing. That amp needs 5 volts to reach full power, so the excessive output of this preamp, wasn't. Wish I had the money to buy one of those amplifiers.
https://orchardaudio.com/product-category/diy/