Vox AC30H2

[soundmasterg]

Vox ran such high gain on the EF86 in the vintage amps that used one that they are prone to microphonics. If they would have adjusted some of the values of the circuit, they could have got mostly the same tone but much reduced susceptibility to microphonics, but they used the same exact circuit as the vintage ones in the modern Vox amps that use an AC30, so of course, lots of microphonics. The way they run the circuit, the screens usually have voltages that are higher than the plates by a bit, which isn't how a pentode is supposed to be used.

Greg

[Ric-O-Buc]

That's some great info there, thanks for sharing it. The NOS Mullard short mesh just got here so I'm going to try that and hope for fewer rattles.

[paologregorio]

Hmm, I might have to pick a couple of these up.

[soundmasterg]

Generally the vintage GEC EF86 is considered to be the best, though the Mullards are up there too....but often the NOS ones will be more microphonic than new ones. They do, however, sound much nicer......more harmonics and a more even and smooth sound. The Svetlana/Sovteks are harsh and have a LOT more gain than vintage ones, but even so they still sound good and are mostly reliable. the JJ's have slightly more gain than the Sovtek sometimes, but I think they sound better myself. I'm using the JJ in my latest modified Vox AC100 build that I've added an EF86 to, but I might experiment with some NOS ones. I'm designing/building the amp around JJ tubes though for possible future builds in case anyone wants one. They are generally reliable and available. In the AC30, EF86's and even 12AX7's are often microphonic due to the circuit design, and to being in a combo chassis and Vox not using an insulated/isolated socket to stop vibration. My 1993 Korg AC30 has some moderately microphonic 12AX7's in it, but I don't mind microphonics as much as cone cry/ghost notes.

Greg

[paologregorio]

The microphonic character of even the new EF86s is significant enough for Korg/Vox to wrap the tube on the new amps with some sort of funky adhesive padded mute around the tube when the amp is built.

[Ric-O-Buc]

The microphonic character of even the new EF86s is significant enough for Korg/Vox to wrap the tube on the new amps with some sort of funky adhesive padded mute around the tube when the amp is built.

I believe its heat-shrink tubing.

The JJ I replaced it with was a great improvement.

[paologregorio]

The microphonic character of even the new EF86s is significant enough for Korg/Vox to wrap the tube on the new amps with some sort of funky adhesive padded mute around the tube when the amp is built.

I believe its heat-shrink tubing.

The JJ I replaced it with was a great improvement.

*!@#* it, Steve; with all of these H2 upgrade posts, you're inadverdantly talking me into upgrading the tubes on an amp I'm already over the moon with satisfaction about.

[Ric-O-Buc]

Speakers now starting to break in.... I don't know why everyone bitches about the Chinese Blues. This thing just sings.... its now my favorite, and I have a vintage Deluxe Reverb and a Carr Vincent to compare it to.

[paologregorio]

Speakers now starting to break in.... I don't know why everyone bitches about the Chinese Blues. This thing just sings.... its now my favorite, and I have a vintage Deluxe Reverb and a Carr Vincent to compare it to.

I don't either; I have a pair of English Alnico "Bulldog" Celestions, and the Chinese built Alnicos. I can't tell the difference.

[8mileshigher]

*!@#* it, Steve; with all of these H2 upgrade posts, you're inadverdantly talking me into upgrading the tubes on an amp I'm already over the moon with satisfaction about.

What's the Freudian term for it, Vox-Mod envy ???

Speakers now starting to break in.... I don't know why everyone bitches about the Chinese Blues. This thing just sings.... its now my favorite, and I have a vintage Deluxe Reverb and a Carr Vincent to compare it to.

I don't either; I have a pair of English Alnico "Bulldog" Celestions, and the Chinese built Alnicos. I can't tell the difference.

I think half the controversy over on the Vox forums about the Chinese Blues was that guys thought they had been deceived into thinking the Chinese Alnico speakers were the English manufactured ones, with deceptive advertising being used, and ambiguous references to England, and Union Jack stickers and the like. But I can't really remember too many Vox forum members saying they could actually hear the difference between them....

Beauty is in the eye of the beholder. Probably just a lot of those complainers on the several Vox Forums were having trouble, in general, accepting that Vox was outsourcing production.

[Ric-O-Buc]

I did my first gig tonight with the AC30H2. Before leaving for the club, I swapped the EF86 (JJ) for a NOS Mullard mesh-plate I bought from KCA. I thought it sounded extra bright at home - but in the bar and at about 25% gain - woah! What a great sound, especially with some overdrive. I played my K-Line strat with Lollar pickups through it. What a nice - singing lead tone came from the amp, many comments on the sound (positive) . I think I've found my new favorite sound...The 330 sounded nice and full as well -

I have no idea what the people who dis the Chinese Blue Alnicos are talking about - these sound fat and sassy!