a glorious tube, and such an easy amp to build (except for gridstoppers needing to be as close to the pins as you can...these things oscillate given the chance) Salas HV shunt supply, edcor TX (cheap as chips), 4.7uf caps on outputs. Simple design and Salas has done the hard work with the...

check solder joints on the socket itself. It could be a dirty pin / socket (I use a needle file for sockets....its well worn though so not too rough) If all that fails... you may need to replace the socket.

http://www.valvewizard.co.uk/heater.html

200ohm will be fine if the wattage is ok, may not need to parallel. i used 220r back in the day

they arent gapped for any DC, so you would need to parafeed them. but.... that cap can be small and premium. You would be right to question the gains over the the current caps you have in... but could you impendance match for all headphones. Thats the biggey

@L0rdGwyn great work, looks fantastic. Pretty much the mods i did years, but yours looks the part... mine only sounded it. Crazy idea... there is enough room on those PCBs to fit the edcor 10k tx..... maybe....

Looking through so many valve amp threads there are so many that are OTL (output tranformerless). Do we think its just economics? Good 470uf low esr electrolytics are about £7 each. Reasonable performing transfomers can be had for £20, really good transformers are ~£100 each. I have three amps...

Whilst not over enamoured with the sound signature (afraid i like big bloomy mids too much), for the money i found the build quality to be excellent. certainly better than my audiotechnicas m40, which creaks and groans with any movement.

I will give them some time, I don't think it's a case of burn in, more my brain getting used to a different presentation

After buying the takstar 580s and finding them amazing value with a small change of pads, I thought would try the pro 82s. So, how are they? As the frequency chart says. Good bass. Thin mids. Good treble. Compared to the 580s or senn 650s, The mids are poor. Voices don't sound full enough.

Very true

Yeah, they sound slightly hollow and with stock pads nasal. Compared with the 650s which sound like syrup in the mids. I think I am talking upper mids or the female vocal range.

Yeah, good description. They are detailed. Bass is warm, mids neutral if a little recessed

Nice. I will have a study. I have been playing with the IXTP08N100D2... In a CCS it sounds better than the dn2540

I can't remember if I am honest. I have a feeling I elevated the heaters , but it's probably 10 years ago, and a lot of whisky has been consumed since. I am currently living my 6e6p parafeed. Would be interested to see more of your gyrator PCB. Any issues with oscillation when Fed with a reg ?

Salas shunt, on horrific perfboard as none of the PCBs available fitted. Had to be sinked through the chassis from memory.

i did something similar to a mates darkvoice. CCS made a big difference. Caps then helped. Power supply was icing on the cake, but least noticable after the other mods. I assume because the cascode CCS was such a brickwall to power supply noise... wouldnt stop me though!

reading back through this thread... how on earth are people describing this headphone as bright? it makes my hd650 sound bright. I love the dark, warm presentation. I can wear them all day, they never get tiring.

built this afternoon! Siemens d3a

6e6p-dr parafeed amp, regulated supply, sic diode bias... and its stunning. blows my old OTLs out of the water. Chinese planars :wink: aluminium drawer handles to protect the ragdoll cat with learning difficulties from itself....

hf580 if you are prepared to buy the avia earpads. turns a a weird sounding headphone into an excellent one.

The 'tinker board' works so well. incredibly quick to swap tubes, swap current, swap bias, all without soldering, and all accessible from the top.

have been messing with the tinkering board. 6e6p-ev @ 30ma and 160v are shockingly good. i think i prefer this £3 tube to my now worth £120 c3g.....

sadly not, just siemens. found a new tube i love... 6e6p dr. as good as the c3g to my unlearned ear. and £3

just recieved mine and had a play. Firstly, they sound better through my valve amp (parafeed, siemens c3g valve) than my solid state. Stock pads = odd mid range. Ever so slightly nasal, probably a slight rasp around 4khz sendy avia pads = glorious. Soundstage increases, imaging increases...