Was gonna just chill and enjoy my DV with my TS 7236 & 6SN7GTB but then this happened…
“but you said that you weren’t gonna lose your head?” yeah right. LOL
Raytheon JAN 6080
GE 6080
Tung Sol 7236
GE 6AS7G
RCA 6SN7 (x2)
KenRad JAN-CHR-6SN7GT
TungSol JAN-CTL-6SN7GTA
Sylvania 6SN7WGTA
Hytron JAN-CHY-6SN7GT
RCA 6SN7 (smoked/grey glass)
Got a good deal on this lot, now I have a ton of shit to play around with.
your favorites? Im currently trying to roll some tubes!
I’m still sticking with my tungsol 7236 as my power tube (just a great tube with lots of warmth and tight bass). But I’ve been loving the hytron jan-chy-6sn7gt I picked up in that bundle paired with the 7236 . I also still roll my tungsol 6sn7gtb as well since it is comparable to the hytron but with more air.
RCA 6080 power tube, and just about any Tungsol pre tube.
I like the combination of the Telefunken 6080 and NOS Tung-Sol 6SN7 or Ken-Rad VT231.
Where did you get the 7236? I just received winged C and it’s humming pretty bad…
Disregard, I found one on eBay. Worth it? I have the Tung-Sol 6SN7GTB. The winged C had good reviews from the tube store but mine had a bad buzz. With the volume all the way down it was bad. Both left and right.
The Darkvoice, in general has issues with hum by design. You have some options. 1 is to spend money on a ton of tubes until you find one that doesn’t buzz. 2 is if you are handy with a soldering iron, perform the fitz mod. 3. If you are really technically sound, replacing the transformer entirely. I ended up doing the Fitz Mod on mine and it worked. If you google fitz mod darkvoice, you should come up with some head-fi threads.
Ok thanks! The stock tubes had zero issues but when I switched the power tube it buzzed. I’m going to let the tube burn in a little and see what happens. And I’ll switch to another power tube and go from there. Thank you!
NP…burn in on tubes can fix the matter, just be careful.
Yeah, I think eventually I’ll build or get a better tube amp. We’ll see how this goes for now.
I understand. I Fitz modded mine. It took some courage as I have only used a soldering iron a few times. I was surprised at how easy it was. Eliminated all hum and buzz. The only hum/buzz that I hear now is if there is something wrong with the tubes. 
I do like to tinker with shit haha. May give me a weekend project. 
Ooo Darkvoice Hum, I have mine here and I gotta say, best solution for me was ripping the transformer out and slapping a new one in. Hardest Part of the Ordeal was melting the Silicon they use to keep the DV box-case thing covering the Transformer. After that the Transformer has the Company’s Website on it, just contact them and get a new transformer from them. Oh that and soldering the transformer back onto the board, if the 135V leads are too long the damn board won’t fit right cuz the wires push the board up and bend it, and too short and it becomes a nightmare to solder those wires. Besides if you try too many times the actual metal contacts on the board come lose and you can pull them off accidentally, thankfully the holes have contacts on both sides so you can pull one accidentally and still have a second shot. Also the Heater Wires Too, those being Thicker due to having Higher Current tend to also push the board up as well, although those don’t need to go on the board, you can just solder those directly to the 6AS7 Tube socket and go from there, it just looks a bit nicer coming from the Board.
Overall it was a super duper annoying ordeal and sucked dong, but it was worth it. Heater voltages are now ~6.3V (When under load) and the amp is quiet with any driver, even my Kenrad VT231 and that thing is microphonic on most other amps, and Doubly so on an Un-Modded Darkvoice.
Hum-Fitz (Cathode Bypass Cap) is another solution, that or Dropping Resistors, either one works well too with relative drawbacks. The Caps don’t actually fix the Heater Issue and introduce possibly unwanted Gain, and the Resistors have to be calculated to drop the right amount of voltage, so essentially just disconnect the heaters from the tubes, and check the voltage with a Multi-meter when you turn it on (The Heater Voltage here isn’t deadly but the amp will still have High Voltage where the plates go, which can be deadly), then just do the correct math for the resistance required to drop that Voltage + Heat Dissipation Necessary as well as the space you need for said resistors.
Also no matter which solution you choose, I recommend twisting the Heater Supply so that it can reject some noise somewhat or at least even it out. Besides It Looks Neater That Way, Less stuff.
And If you REALLY want to reduce noise more maybe after making twisted heaters, add a third bare wire that coils all the way around the Heaters as tight as possible (Without messing with the Heater Wire’s Insulation tho), and plug at least one end to ground to act as shielding. Also do that to the Signal Wires too If you want although I think it already does this if by chance you never replaced the Potentiometer.
If you do go the Hum-Fitz Route, maybe replace the Cathode Resistors in the Driver with LEDs like in the Bottlehead Crack (Your choice tho). Also The Noise mostly comes from the Driver not the Power Tube, so concentrate your efforts on the 6SN7 if you’re just in it to remove the hum.
For the Fitz mod, you install 2 Nichicon VX Axial Series Electrolytic Capacitors - 16volts 220uF. Works like a charm. It will hold me over until I build my bottlehead crack.
When you installed the 220uf did you get more gain or is it the same? Heard 100uf works as well and the gain increase is more subtle? Oh Also if you really wanna throw money at a problem, just buy this cap https://www.partsconnexion.com/MUNDORF-80530.html
Afterwards just put 10 of those in parallel per cathode (For a Total of 220uF) and watch as you essentially spent the equivalent of 2 years of my student grants in a fix for a Chinese Tube Amp. That is the Remy Buxaplenty Way, I think?
Oh Forgot to ask, Bottlehead Crack w or w/o Speedball? Cuz if you’re gonna go Speedball maybe just save up a bit more for a Crackatwoa without the Two-Step Attentuator, It Uses Shunt Voltage Regulators from the Pentodes for the C4S Loads of the 12AU7/6080. Essentially Higher Current Versions of the C4S Found in the Crack, and maybe Equivalent to the C4S “Speedball” for the 6080 of the Crack as well from the look of it, maybe a bit more sophisticated or designed for more than 30mA? Like both the C4S for the 12AU7 Plate and 6080 Cathode C4S are being Regulated this way from what I could imagine, which I’d also imagine has to sound dope, and possibly can be pushed to be superior than the Mainline, maybe Cathode based OTs for a 600ohm/8ohm system? Ooo maybe a switch to turn it from OTL mode for High Impedance to OPT Mode for Lower Impedance. Pretty simple mod too if you just use the 119DA OT. Then Again the Power Transformer is damn Beastly capable of handling a 6528 with some Grid Resistors to stop Oscillation allowing for some lower Impedance stuff.
Whoops got off topic but got pretty excited. Might get a Crackatwoa just to see if the Shunt regulator can work with Two C4S loads per board, has me curious, maybe just test it with an altered Stereomour II Shunt Regulator and a Crack and see where that goes too?
My gain stayed very similar,…if I gained anything it would be maybe 5% more. What is interesting is I can even use low impedance headphones on the Darkvoice now without them sounding bad.
I cant really explain how the heck that happened, lol.
How Low of an Impedance though? And Does it not sound bad but also have low volume, or do they get loud and Sound Good? Also what tube cuz 5998 and other tubes reduce output impedance.
I have a few 6080, a few 6as7g, 1 6H5C and 1 7236. I actually prefer my RCA JAN 6as7g or my Mullard 6080. With low impedance I do use 6080 obviously. Still don’t understand the magic of the Fitz Mod, but I’m happy I did it. Not every low impedance pair of headphones sound good on the darkvoice, but I did find a few.
The high impedance Sennheiser HD650 or HD600 and Beyerdynamic DT880 600 ohm still sound the best on the darkvoice, without question. My RCA 6as7g I typically pair my my RCA 5692, Ken Rad VT-231 or Tung Sol 6sn7gt mouse ears. The Mullard 6080 and the Tung Sol 6sn7gt mouse ears or a Sylvania 6sn7gt bad boy.
Maybe the slight gain increase due to the Hum Fitz aided this a bit, although idk if it’ll help much with Planar Headphone. My Darkvoice with the Transformer Swap + Reduced Resistance to the Driver Plates (Voltage Increase) seems to work well and power well up to 33ohm (M40X) With very very minimal Bass Loss, I got Mundorf Coupling Caps at the price of Halving Capacitance, makes HD600s and T1Mk2s Sound Great Though since those don’t really care due to they’re High Impedance.
It can also power Aeons but Lose a ton of bass and get a really Anemic Sound, even a bit of “Fuzz” like the static of an old TV or something when playing music, even if they can get Audible-Loudish. Amp is quiet though with anything, even low impedance, it just doesn’t work well with those once the actual music is playing you know?
Yeah, typically planars and OTL amps are oil and water…just don’t work well together.
I popped in a pair of Grado SR80e and they sounded good, but volume was obviously very loud…lucky I have a DAP as my source that I can control volume with like a preamp of sorts. DT770 80 ohm, AKG K712 and Neumann NDH 20 sound pretty damn good also.
