I'm thinking of modding this and putting in a set of HY69, which are similar tubes only they are Thoriated Tungsten and are directly heated. I will have to DC heat the filaments which will probably require a seperate box to house the filament supplies.

Whipped this amp up in a rough test chassis to drive planars. Its a single ended 807 with 6j51p driver. Amps uses plate to plate feedback (Schade) with the 6j51p running in pentode mode. All screens are regulated with VR tubes. The driver tubes use regulated DC heaters I tested the amp with the...

260mw into 4 ohms. I put a pair of 5 ohm resistors in parallel to the cans to reflect the correct load for the 6AK6.

Just got done with this amp to power my Symphones V9 custom Grados. Sound is excellent! This was probably the smallest transformer coupled amp I have made! This is truely a junk box amp, I got maybe $20 in it lol. I also powder coated it myself. Puts out around 260mw of power!!! Output tube is...

Just got done with these; the drivers are 40mm 32ohm ribbon tweeters from speaker addicts. I had to get a little creative to get the drivers mounted. The wood cups are from "therewillbedust." I still need to order a nice headband. Fired me up on one of my DIY tube amps.....they need more than...

Just got done with this amp to power my Symphones V9 custom Grados. Sound is excellent! This was probably the smallest transformer coupled amp I have made! This is truely a junk box amp, I got maybe $20 in it lol. I also powder coated it myself. Puts out around 260mw of power!!!

Just got done with these; the drivers are 40mm 32ohm ribbon tweeters from speaker addicts. The wood cups are from "therewillbedust." I still need to order a nice headband. Fired me up on one of my DIY tube amps.....they need more than 260mw lol. I will probably breadboard a 807 in SE pentode...

Made a couple mods, increases output capacitance and changed 6N3p to 5670, more better all around 😁

Sure did 😁

Damn....this amp is fast and has DETAIL for days!!

Everything is sorted out, sounds great and has no problem driving 32 & 70 ohm planars!

Well, got it mostly figured out and running go a ground loop on left channel, but I think I know what caused it. Also....where in the hell do I ground the VU meter board, it only has one input ground... pretty sure it will cause GND loop? Will report on sound when I get it all ironed out...

I forgot the current sense resistor on the WCF

Well, that wasn't the problem. It's like a weird, loud, grinding sound

NVM, figured it out; I had the output from the SRPP stages taken from wrong side of resistors

Well, the good news is it is not the chokes. The sound I heard was oscillation coming from my test headphones. This will be a pain to hunt down for sure

Good idea. Im going to run the amp with only the rectifiers and no other tubes and see what happens. I tried it with the tubes and no rectifiers and there was no issue.

Unfortunately, they are sealed transformers. I may redo the power supply with SS bridge into parallel 6D22S (for slow turn on) then use current limiting resistors. Im not 100% sure the buzz was from choke as I turned off the amp pretty quickly. Could be the toroidal power transformers. I was...

Well, we have a problem, I think one of the chokes are FUBAR, huge mechanical buzz...still troubleshooting!

Well, we have a problem, I think one of the chokes are FUBAR, huge mechanical buzz...still troubleshooting!

Marantz 2230. I have restored over two dozen receivers, and the 2230 is probably my favorite.

Super OTL headphone amp, just finished it, haven't fired it up yet, maybe in the AM. It runs 6N3P SRPP input into SRPP 6S19P driving 6C41C WCF outputs. Power supply is dual mono using 6D22 rectifiers in hybrid bridge. Amp is overkill, but I don't care, it weighs in at over 70lbs. I powder coated...

Welp, here it is.... haven't powered her up yet, maybe in the AM when I'm fresh into it

I'll check it out; I have Morgan Jones book.

Yeah, the Russian datasheets leave much to be desired for sure. I will say that every time I have built an amp with Russian tubes, I have been more than happy with the sound! I have decided to drop the choke loaded input stage because I have ran out of room under the chassis and I am afraid of...