what kind of input tubes did you try ? Sounds like you're having bad luck with noisy tubes... also try to go single ended out instead of balanced, and low or medium impedance setting. this will reduce the noise greatly; balanced will be perfect with no noise with low sensitivity headphones (...

The amp will not explode if you forget don't worry ;) the switch is for optimizing the operating points for the tube types, I don't know exactly what it does, but I speculate it is adjusting bias and maybe plate voltage. that said, if you leave the switch on the kt88 position and put some el34...

Ouch too bad to hear this ! that sounds to me a lot like The HT fuse has blown up. have you changed the fuse on the power supply board inside the amp ? ( not the one under the power cord ) for 220V it should be something like 250ma slo-blo, if I recall correctly ? maybe @Andykong can confirm...

hey guys, Just to let you know, I have a burson soloist 3X Performance coming to me the next days... together with a gustard X26 Pro Dac, so I will be able to do some comparisons with the HA-6A ;) I will have some stuff to write down in the next weeks, so stay tuned ! Also @Relaxasaurus I...

yes, no problem, I have mine right next to my 32' monitor on the desk, no problems, and doesn't affect noise or sound . Just be sure to leave a bit of room for air, as it can get fairly hot

hello, the rule of thumb about impedance matching for TUBE amps, is you should try to match the amp and transducer impedance to have optimal power transfer . tubes being voltage amplification devices, they tend to be more powerful with higher impedances loads ( more Volts into more ohms for...

I think the kt66 may be worth a try as well, those are evolution from the 6l6 family. Tung sols 7581A are also highly regarded.... So many options ! I also have tried the blackpkate kt88 from tad, they have super bass, and very linear and energetic sound, great for metal music ! ( you should...

Hello I bought a quad of Sylvania 22de4 from eBay for cheap, they appear to be exactly the same as the RCA originals. No change in sound detected they seems to be hard to find indeed, I don't see them very often, and there is no new production tubes to replace them, or suitable NOS replacement...

Are those the gold lions kt77 ? If yes they are very nice tubes indeed ! The kt77 is stated by a french tube expert called francis ibre, as the pinnacle of the el34 tube evolution ! I may try those in the future , now I am focusing on other aspects of my audio chain, especially on cleaning the...

Ah too bad you didn't like them... seems to me like a faulty unit ! I use the utopia on my ha 6a with 1/4 cable and they sound great. With plenty of bass. I also have a hifiman arya. And to my personal experience. The utopia sound more full bodied than the aryas ! Bass is even stronger. More...

You will be fine with either, the dc plate voltage is only a max rating on the datasheet. The 6l6wgc blackplate is one of my favorite tube for this amp. I have not tried the new red base version yet. If you get those I wish to know how they sound like ;)

I bought them direct from tad in germany, took a few days to arrive with ups ;) But I live in france not far from the german border... so that helps with shipping, no idea how long it will take to arrive in the us, I will say TAD are very nice to deal with. I also got nos sylvania 12bh7 from...

Yes there are 2 grade levels, the str version, which is cheaper, and the blackplates series. The second picture is the tube I have, and I was talking about this tube in my previous post. Sorry if it was unclear, I am not a native english speaker ;) The tubes branded TAD, means tube amp doctor...

I have to put the gold lions back in the amp, and the blackplates need a bot more burn in. from memory I will say that soundstage seems wider, and tone a bit richer, bass seems is great, but cannot confirm for the moment. I will report back when I have swapped between them

Yes I have received this morning Tad KT88-STR Blackplates, they are on the burn in phase now but they sound already very nice right out of the box, more on those later ! usually if you want to fatten the sound, go For JJ power tubes, like JJE34L or JJ6550. Maybe even the JJ KT88. I have a set...

hello andykong, I appreciate your answer, and totally understand your point of view. My Ha-6a is past it's warranty date of 1year, so yes I personally took the risk to try it for myself. I also made big disclaimers and was particularly clear that doing so has it's own risks and that any person...

For those you want to know here is the adapters I used https://a.aliexpress.com/_mrUwWRV Socket savers are pretty easy to find !

Guys please if you want to try this do it only wirh 6l6 tubes on the power. Unfortunately i couldnt check the rating of the power transformer on inspection. So unless cayin says that the power tranny has enough headroom, i would advise against doing it... 6sn7 to kt88 adapter ???? Never...

Hello guys, I wanted to share a little tube experiment I am doing at the moment with my ha-6a. disclaimer: First please, this my personal experience with my amp, please do not try to reproduce what I am doing here unless you know what you are doing, and then you are doing it at your own risk...

Have you heard them in the ha 6a ? I was evaluating between the 6550 and kt88 blackplates for my next try.... I have too much tubes XD It is going out of hand.....

My friend, You want the 6l6wgc blackplates Those are the ones I personnaly prefer, they have spent the most of time in my ha 6a... https://www.tubeampdoctor.com/en/6l6wgc-str-blackplate-ge-style-tad-premium-matched?number=RT812 Or from your russian seller, try to get tung sol 5881. I have...

hello my friend, For KT KT120 and 150 I don't think they will be compatible, because the heater current needed is higher than kt88 (1.9A vs 1.6A), and it will put more effort in the power transformer. that can result in more heat generated as well as transformer core saturation. Unless...

It is indeed not a common thing in hifi world, but all guitar tube amps in the world has a gain control... together with tone stack etc...and several gain stages HA 6A has the volume pot before the preamp stage, should be possible to add another pot between the preamp stage and power stage, so...

good for you then ! the pairing must be very good ! have you tried the zmf with a balanced headphone cable as well ? with mine, it is noticeably higher with balanced cable.

That will be for a nice christmas gift !!! let's hope that it will be the answer !