DIY Front End 2022

Not very much to do a mistake. All 3 were 250r and were inserted in the same socket. Nothing else changed.

Unfortunately I didn’t do any listening tests but lowering so much the 3rd hd convinced me that I have to spend the money for the caddocks in the line stage project that I want to build in the next future.
Hello Frontend2022-builders,

I finished stuffing the original pcbs, which arrived a few days ago. The J113s from the essentials-kit are nicely matched.
Thanks to Nelsons son.
Now I want to compare the original against my own pcbs (although I think there won't be an audible difference).
This will be the plan for this weekend. I am running them from a symmetrical PSU (linear regulated) at +-20V DC.
Have fun building and listening to this nice circuit!
Dirk :)


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Re: resistors and distortion

For me, it would depend on the actual amounts of distortion. Was it 0.01%, 0.02%, and 0.04%, or was it 0.1%, 0.2%, and 0.4%? Or something else?

Also phono preamplifier, line preamplifier, power amplifier, or something else?

And of course, was the difference audible?
It was a line stage, and the 3rd went from 0.003 to 0.00075.
To lower the 3rd in an ops 4 times you have to increase the bias a few times.

I didn’t do any listening tests but I know now what I want(lowest possible 3rd) and the graphs were enough to convince me. I will do listening tests when all will be ready and I will adjust the amount and phase of 2nd, yes in the linestage.

So I preferred to run my amps cooler and spend a few more bucks to solve it in the line stage.

If I got it right all these years, you have to aim for the lowest 3rd this permitting you to alter the second as you wish.

Nelson said somewhere that these amps sound good with high second or high third but not with both high. It never went bad when I followed him.