Hiwatt related power tube question...

[JeffreyC]

I've read over at the Hiwatt forum a few times that the power tubes in the typical Hiwatt amp circuits (Custom 50, 100) have much less of an impact on tone than the preamp tubes. If that's true, then what are the technical reasons behind that? What's going on in the circuit to make the power tubes have less of an impact on the tone of the amp?

...and just because I like the reliability of NOS tubes and the tone, what are some good suggestions for NOS EL34's close to Mullards without the price tag? I need a matched pair to replace the JJ's in my Reeves Custom 50!!! :crazy

Thanks! :BEER

[Ferrari-Dude]

Sylvania 6CA7 are what I use. They are robust and sound tight. The 6CA7 is an electronically compatible equivalent but will sound a bit different than the Mullards.

Hiwatt's are hard on tubes, so you need good tubes.

[John Phillips]

Regardless of that they say so on the Hiwatt forum, IMO it's wrong. The power tubes have a large effect on tone and reliability in Hiwatts - as in most amps IMO.

I tend to find Siemens EL34s (narrow bottle/dimple-top, not as rare or expensive as Mullards - and often found cheaper under numerous different brand names, if you know what to look for!) work well.

[JeffreyC]

Bumpsky!

[Blue Strat]

SED EL34s or Groove Tubes EL34Ms are good economical alternatives. Next step up, NOS Tesla EL34s.

[Swarty]

I think I understand where they are coming from. The Hiwatt power amp is designed to run clean/linearly at all volumes and thus adds very little color (grind, distortion, harmonics) to the overall sound of the amp, especially when compared with a typical Marshall. The signal coming out of input preamp tube gets amplified over and over throughout the circuit and thus plays a large role in the overall sound of the amp. Other preamp tubes have a much lesser impact.

[Tripower455]

I've been using NOS Tesla EL34s in my Dr504 for the last 2 years. Sound great and no issues at all.

Oh, and I've found that "the" Hiwatt sound comes with the master UP!

[JeffreyC]

SED EL34s or Groove Tubes EL34Ms are good economical alternatives. Next step up, NOS Tesla EL34s.

Thx for the responses guys. Yeah, I've been thinking of ordering a matched pair of those Teslas from you for a while now. I might place an order this week Mike.

[Hiwatt Bob]

hey jeffrey, i think i was the one who said that--and in context, i certainly didn't mean to say that power tubes didn't have a tonal effect. just that preamp tubes (particularily V1) have a much bigger impact. i bought a stockpile of NOS/used tubes because there was a significant change in tone--i could tell the difference between a mullard and a JJ. output tubes, in my experience, only seem to have a real impact in hiwatt's tone when they're totally dimed. then you can tell some tubes break up differently than others, etc. but i rarely run my hiwatts dimed. and still, comparitively speaking a swap in V1 makes a much more noticeable difference than different output tubes. when you consider that a single mullard ecc83 for v1 only needs to cost you $x and will last a really long time and will impact your tone more than a pair of NOS EL34's which cost 4 times as much--it just seems more prudent.

i too have some teslas in my DR504, and they were an improvement from the svets (new sensor) that were in there. but for my 100watter--i'm not going to spend crazy dollars on a matched quad...when i'm happy with JJ's EL34L's. But the tesla's sound good and are very durable. from what i gather--the siemens sound good, but sometimes have a hard time standing up to the high plate volts in a hiwatt.

[JeffreyC]

hey jeffrey, i think i was the one who said that--and in context, i certainly didn't mean to say that power tubes didn't have a tonal effect. just that preamp tubes (particularily V1) have a much bigger impact.....

Thanks man. Yeah, what you're saying does make sense. I definitely notice way more tonal difference when swapping out V1 in my Reeves(Hiwatt) amps than any other tube - in both my Studio Stage and Custom 50. What do you think of the JJ EL34L's vs JJ EL34's? Maybe I should get another NOS Mullard 12ax7 (maybe a long plate) and buy a pair of Mullard Reissue EL34's. Decisions, decisions...

[DC1]

I have a 1969 HIWATT DR103. NOS for preamp. SED or JJ for power amp.

ALL of the NOS power tubes are stupidly overpriced. The new-production tubes work well and seem to last at least a year for me, and they sound great.

Preamp tubes last a long time, power tubes do not. NOS power tubes are not a real-world solution, and the prices are piracy.

DC