First channel up, seems to balance fine. A few more measurements are up. Then moving on to the second board, after reversing the LED (damn greenhorns
) and soldering output cables in with needle pins, and some signal wiring of the finest sort 
Plan is to finish it up with scope and residual waveform analysis, once all else is done.
If not for you this would have never come into fruition. Thank you! So need to honor that somehow. I try to do that by working meticulouslyLooking good Andy!
The same goes for Papa, good friends who know who they are, and some friends one did not know one had
2nd chan up. Both may need a bit up Iq bumping, but we will see what happens with a proper PSU. Now for some chassis and PSU work
Insanely excited about this project, can’t wait to listeb to it.
Btw, gate reverse leakage current is 18uA for right chan and 22uA for the left. Works fine with R6 @ 8K2, range to spare.
Ok ok, so I forgot accreditation. And yes, I mean JFET gate reverse leakage current.
You are so perfect it is hard to keep up
Metodological accreditation: MZM
Circuit accreditation: Grand big Papa San
Layout/board accreditation: Twitchie
Fet accreditation: Can’t remember
Advice underway: Dennis and MZM
Happy? No?
Edit: yes, GH’s are always obsessed with Iq.
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you can freely leave out MZM from (any further) accreditation .... we all know that MZM is responsible for all successesssss around, while ookups are completely on each particular Greedy Boy
when it'll sing?
Dunno when it will be ready. Everything is done in between family chaos and work, so everything is readily available to work on all the time. It is the only way I can finish anything at all really.
Before Christmas, but hopefully before the end of this month
Up and singing. Best sound I have experienced so far in my DIY travels, extreme in fact. Smoothness and warmth - a tonality out of this world, dynamic as well. And more bass as expected with my FR’s.
Iq adjusted today by parallelling across the source resistors.
To my huge disappointment the audio grade Toroidy in fact buzzes. Will try a DC blocker, but this is really subpar and way below expectations.
Measurements and fine adjustment pics to follow.
You can also try to experiment with a resistor in parallel with a speaker, it will reduce the gain but you can achieve the critical damping. To me bass is no longer boomy around fs, more details in the bass region.
Regarding Toroidy.. sadly they are no longer my choice when it comes to buy a transformer for PSU. A few years back I got better quality products.
Regarding Toroidy.. sadly they are no longer my choice when it comes to buy a transformer for PSU. A few years back I got better quality products.
Damping is the next experiment/tinkering plan, and network in the mid term. Sadly this crappy transformer has my attention at the moment. What is your choice these days?
Got 300vA’s for my AJ. Though run at lower currents and therefore not directly comparable, they are completely and utterly silent. Not possible to hear they are on.
E-mailed Trafomatic yesterday, let’s see if they ship custom trannies abroad.
Emailed Toroidy too. I’ll let you guys know their response.
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I understand the rationale, but please explain why I should bother (pretty pissed, and Trafomatic has answered my emaildiconnect one channel ,if no buzz ad a second ones
dos as mejo de one
) ?I could reverse phase. But Toroidy has confirmed this has no effect. Though ime, I have experienced buzz reduced when swapping secondaries. Let’s just say all efforts need to be worth it. Everything, EVERYTHING, is soldered. Since I had great confidence in these parts…
What I can say is that the buzz level seems current dependant. Perhaps a loose windingc dc on the mains, a saturated core (though well under 50% of the rating), and or a combo…
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That would be an interesting test and may give more indications of where the problem lies, but I would not consider that a satisfactory solution. After all, my understanding is that Andy is using a 400VA transformer and it should not have a problem handling the standard current load for both channels.
I understand the rationale, but please explain why I should bother (pretty pissed, and Trafomatic has answered my email
I could reverse phase. But Toroidy has confirmed this has no effect. Though ime, I have experienced buzz reduced when swapping secondaries. Let’s just say all efforts need to be worth it. Everything, EVERYTHING, is soldered. Since I had great confidence in these parts…
What I can say is that the buzz level seems current dependant. Perhaps a loose windingc dc on the mains, a saturated core (though well under 50% of the rating), and or a combo…
If you got positive reply from Trafomatic, just say them that they make Donut by same specs they are making for Prodanovic (if you need more details, buzz as usual
)I did ask them are they willing to send their Donuts abroad (so I can pass their info here) and they weren't in mood, at a time
They are apprently in the mood to satisfy Prodanovic’s friends. Or at least, people who would like to be his friend/wrongly say that they areIf you got positive reply from Trafomatic, just say them that they make Donut by same specs they are making for Prodanovic (if you need more details, buzz as usual
I did ask them are they willing to send their Donuts abroad (so I can pass their info here) and they weren't in mood, at a time
300vA, wound around a bigger vA core for reduced flux density, or something along those lines? «Buzz»
Or 400 vA? The more the easier saturated by DC, so which way to go?
PS: I know you use 2 x 300vA for FW current levels. What would be your recipe for just one tranny?
Hugz,
Yours truly
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