HeadAmp GS-X Mini Balanced Headphone Amplifier/PreAmp

What kind of tubes for WA33?

At least you can still find matched sets, I used the Sovtek in my Guitar AMP from time to time.

I have bit of tube tending with few Power Tubes: El34, EL84, KT66, 6v6 and 6L6. On the Preamp/Reverb/Tremelo tubes 12AX7, 12AU7 and, 12AY7 in my current guitar amps. Hence Amp & Sound Headphone amp was my best pick.

I am seeting on Reverb 4 pack or 2a3 are $209 https://reverb.com/item/11962163-plate-current-matched-quad-4-sovtek-2a3-triode-power-vacuum-tubes

Also and 8 Pack is $409 https://reverb.com/item/11962172-plate-current-matched-octet-8-sovtek-2a3-triode-power-vacuum-tubes

How is it going with the Lite?

Im brand new to the tube world. Was always ss person. I’m confused by all the tube brands and what works with a particular tube amp. When I get a chance I’ll post the tubes the WA33 came with.


It is an interesting rabbit hole to run down.

Modern tubes are mainly from 4 manufacturers, note you will see multiple bands. There are still a few boutique manufacturers left as well.

  • New Sensor Corporation US company - Made in Russia
    https://shop.ehx.com. We know them as Electro-Harmonix who early on was known for the Big Muff, Electic Mistress, Memory Man Guitar pedal fame.

    • Brand(s): Electro-Harmonix, Genalex, Mullard, Sovtek, Svetlana, and Tung-Sol
    • OEM: SED, NEVZ-Soyuz, Vaco, and Voshod
  • JJ Electronic inc. Slovak Republic

  • Shuguang Electronics Group in China

Names who buy tubes from the above vendor and rebrand:

  • Groove Tube. -Fender Corp
  • Mesa Boogie
  • Telefunken
  • Peevy
  • Tube Amp Docter Brand TAD

Small guys like

Then you have tubes from yesteryear in two forms, lots of brands here. This is the land of Audiophiles. I will stop there:

  • NOS New Old Stock
  • Used tube

Thanks for asking!

It’s a fun little amp. Plenty of power, and I’m perceiving more dynamics. But that could easily be something like increased bass or maybe even slower decay. But I’m perceiving it as increased dynamics to let’s go with that. It’s very lively and overall is a fun listen.

My comparator right now is a SPL Phonitor e, so any warmth or color is likely to be very prominent. The SPL is amazing though, so I’m sort of setting it up for failure. I’m still playing with it, but as of right now I’m very pleased with it.

As you know it’s light on features (balanced HP outputs or inputs most obviously), so I get why more people don’t choose this in the price range. But for sound quality I think it’s great at $500.


Very Nice. I sound similar to what I was hearing with it bigger middle brother vs the Phonitor x . as you know the x= e in power since it same amp minus VU meters.


This is what I tell myself everytime I enviously look at those VU meters and larger case. :joy::joy:


I saw 2A3 and 6C45. The 6C45 is a new one on me. Might want to verify that one with the manufacturer. It’s not in my Tube Lore or Tube sub books.

Good variants for the 2A3 are 2A3A and 5930 per my sub book. I saw 2A3 was $60 each NOS at where I get my tubes. Kinda pricey indeed.((esrcvacuumtubes.com)).

I would make contact with the unit manufacturer and see if there any other substitutes they would recommend. Keep a set of spare tubes as well.

I just bought a second AS Kenzie and stayed with the same type of amp for tube standardization. My Encore and Kenzie use the same tubes, and tube substitutes. I have a couple of hundred tubes for my various devices. Luckily, they are all fairly inexpensive, or were when I acquired them.

Oh … while I’m not sure why this is in the GS-X Mini thread … the 2A3 tubes used by the WA33 get expensive fairly quickly.

The good ones, at least.

The $250 sets of 4 you’ll generally see (especially on music/pro/guitar fora) … are typically not as good as the stock tubes, let alone the other options.

If you don’t want to step up to a matched quad of at least the KR Audio 2A3s, then I’d suggest sticking with what you have for a bit. Though the NOS RCA 2A3 monoplanes are really the target here (happily my WA234 MKII MONO only need a pair of those).


Is the 6C45 a new production type tube. Don’t see any NOS listings in my tube reference books.

***Didn’t see the minor off-topic drift worthy of its own thread.

We should break this off into a forum thread, I looked. I have only seen on the forum talk about the tube you collect.

On your question, 6C45 was initially built for Soviet military communications and radar applications, the leading supplier is Sensor Corporation, via the Sovtek brand. The DIY audio community is who re-discovered this tube for pre-amp use. Much lower distortion then a 12AX7 with gives you much lower noise floor.

I have WA33 and see Woo charges a lot. My question is are you getting better matched tubes through Woo or going through different vendor be just as equal? By the way I’m finding better synergy with the HEDD on the mini vs tube. Has anyone else come to same conclusion?


Thanks @BondDaBoom THe Mini has his a new friend.

Bifrost is back, XLR into GS-X Mini, RCA into Pendent. RCA into both from the Chord Qutest. The Mini just love XLR input off the Bifrost.

I have to say you could get lost in both setups on a pair of Planners like HE-1000SE and RAD-0.
Now the ZMF Vertie is just special on Pendent.

With the HE-1000 Cat Power “I Have Been Loving to You Long” Vocal are more present on GS-X Mini.

  • Now Amy Winehouse “Back to Black” is great on both.
  • Leading to The Man in Black, Johnny Cash “Hurt”
  • Following him is the modern man in black Nick Cave and Bad Seeds “Wide Lovely Eyes” & “People Ain’t No Good”
  • dive deep into your soul with Janis Joplin’s “Work Me, Lord”
  • how we are “Blowin’ in the Wind” Bob Dylan
  • I live you Rockin’ in the Free World" with Neil Young

For my current crop of Head Phone, I think I have found two amps to give me the balance of detail and lay back experience.

I will leave you one more with all that going in the world. “Shelter from the Storm” Bob Dylan


I just found myself drifting through "The Freewheelin’ Bob Dylan album. GS-X mini with Bifrost and HE-1000 bring out so much richness. I just love how he strums and plucks his Guitar and pure vocals of simple story.


You’re gonna love that amp. Great collaboration by Zach and Justin.

I don’t have one, but know it will rock.


Thanks…Could you use a 12AV7 or 12AT7 to keep the noise down?

1 Like

Right now I loaded the Tubes BondDaBoom sent with it

  • Baldwin 12AU7, 2 EL84
  • EZ81/6CA4

Have you asl looked at the EF86, this way we bring back in line with original AC15 design this based on? or 6Zh32P.

I never used a 12AV7, I am sure it would work, I saw old late 60’s RCA or Sylvania’s tubes I pick up for under $15 each

I have 12AT7 or what I know it as ECC81 for one of my Guitar amps,

For my guitars amps, I collected

  • JJ 5751,
  • JJ ECC82,
  • JJ ECC81,
  • Electro-Harmonix 12Y7
  • Tong-Sol, JJ, Electro-Harmonix, Mullard 12AX7

On the current EZ81, I have never seen this brand

1 Like

When i was working on my Binson Echorec, one of my favorite people to talk to was Phil at Efectrode. He has one best understanding of tubes

Good place to start on Tube learning journey. TUBES

Mullard ECC83 (12AX7) Reissue vs Original – An Electrical Comparison
The ’12AX7′ Tube
The ’12AU7′ Tube

How did it get over there. :cry: :cry: :cry: :cry:

1 Like