What's the worst tube amp you've ever heard?

[Enzo]

As Alex said, the op amp is in the reverb circuit, as is the JFET - NOT the signal path. Turn the reverb down - as if you could hear the transistorness of the reverb anyway - and it has ZERO effect on the tone.

As we both said, the 6534 is the loop send driver, and is NOT part of the signal path unless you use the loop. I have my glasses on, pal, you fouled up the part number of the transistor.

Note that the circuit through Q2 goes only to the send jack, nowhere else. And note that the reverb circuit is a branch off the signal path, so when not in use, the reverb circuit has NO effect on the sound. Stating something like Q2 is in the signal path no matter what is simply wrong, as the schematic plainly shows.

The interesting quality of a JFET is that just sitting there it acts like a low value resistor until you turn it OFF via its gate. About 150-200 ohms is a common figure. The JFET in this sort of switching application then becomes either a series resistor or an open. It does not amplify, add gain, or any of that, it just passes signal through that low resistance. Considering that it feeds a 10k pot, the extra couple hundred ohms in series will not have an audible effect.

Mykey suggests we remove the transistors and listen. OK. One difference we hear is the effects send no longer functions, but the sound of the amp remains unchanged. The other difference we hear is that the reverb no longer functions, but the sound of the amp remains unchanged. Replace Q1 with a 200 ohm resistor, and the reverb will function again, and it will sound exactly like it did before.

As for the Mykey philosophy, I'd say dogma is for wimps.

[Steve Conner]

Yeah, transistors are for wimps like Dimebag Darrell of Pantera. Oh, and Jimi Hendrix, but who ever heard of him?! Maybe if he had got rid of his Fuzz Face, octave pedal and Cry Baby wah (all transistorized) he'd have been famous by now.

The nature of transistorized amps is to deliver tight bass, and huge amounts of clean headroom. When the headroom finally runs out, the distortion that results is pretty hard and ugly, and really doesn't have much to recommend it. This is where the old myth about one tube watt being worth three transistor watts comes from: it's because you musn't let the transistor power amp clip, but you can drive the crap out of the tube one.

Peavey built a nice compressor circuit into some of their solid-state gear that stops you from ever clipping the power amp no matter how hard you drive it. I remember using a Peavey powered mixer with this circuit in, and being shocked at how loud it would go while still staying totally clean, and not burning out the tweeters with harmonics as a welcome side effect. (especially since it wan't my gear...)

Compared to relays, FET switches add some harmonic distortion, because their on-state resistance varies as a function of the voltage you're switching. Apart from that harmonic distortion and extra resistance, they might as well be wire. They don't cause any "delay" that I know of. Mesa Boogie made a bass amp with a front end made entirely of JFETs, and I think slap-and-pop players would have noticed if each note took half a second to make its way through :P

[Alex R]

Hey I learned something about how FET switches sit in circuits, some solid stuff and a bit of speculation - all ok by me. Thanks to those who gave me the detail I asked for.

I'm an amp repairman part-time, pretty busy at the moment and taking in some less familiar items now and then. People on this forum - Enzo in particular, but many others too - have been wonderfully helpful to me when I've been foxed by the unfamiliar or just needed/wanted to learn a bit more. So much knowledge and expertise here, and all for free. Just a priceless resource, well worth preserving. I get a little upset when the quality of that advice is compromised by wild assertions, but that's the magic of the web I guess. It does produce pissing contests now and then, but I say if a really poor pisser is pissing over everyone and you can piss high enough to piss him out of business - then piss away. Ultimately it just makes me more grateful for the good stuff.

[Baxthorpe]

When you talk about getting an overdriven sound by feeding the output of a small amp into a large one, the first examples I know of were by the Kinks in the 60s. They used a small Elpico combo (aka "The Green Amp") as a preamp to get the grungy sound on their early hits - check out "All Day and All of the Night" etc.

[tubeswell]

Well I knew all along that the only transistors in the C30 were in reverb circuit and the FX send, so maybe I know more than mykey, but knowing what I know, that would not be much - heh heh

As for the difference the reverb makes, well I love the sound of the amp and the reverb just makes it a little more sweeter.

Yes I love my C30, esp with the Blue Guitar mods courtesy of Mr Ahola (and a few more of my own mods). And if it hadn't been for the people on this forum, I maybe wouldn't love my amp half as much, so thankyou one & all - The best little tube amp for miles.

As for MOS Fet amps, I had a great 300W bass amp head about 20 years ago, made by Kiwi firm Rockit (now gawn outta business due to import tarriff removals). Was a beautifully clean and punchy amp with two channels and a five band EQ and optional limiter. Shame I sold it to go to Uni - woulda loved to have had it still - it would be priceless now - very hard to find - DANG! Anyone got one for sale? (Rockit 300)

I

[xFallen]

When you talk about getting an overdriven sound by feeding the output of a small amp into a large one, the first examples I know of were by the Kinks in the 60s. They used a small Elpico combo (aka "The Green Amp") as a preamp to get the grungy sound on their early hits - check out "All Day and All of the Night" etc.

Randy Bachman did it in the 60s too : http://www.garnetamps.com/herzog.htm

I think there's some sort of reissue pedal out there somewhere too I remember seeing with Randy's name on it. Found it. Its by Tech 21.

My recollection aboput the Kinks for those early recordings is that Dave Davies slashed his speaker to get that tone, initially at least. He may have used some sort of device later, or maybe the speaker thing is over blown.


Barry

[tubeswell]

My recollection aboput the Kinks for those early recordings is that Dave Davies slashed his speaker to get that tone, initially at least. He may have used some sort of device later, or maybe the speaker thing is over blown.


Barry

Didn't Link Wray do the same thing to get the sound on "Rumble" a few years earlier?

http://www.youtube.com/watch?v=PP0aRKnyzpc

[Steve Conner]

Well yeah, like tubeswell said, there's nothing wrong with transistors and MOSFETs if they're used properly. In musical instrument applications, that means adding some sort of limiter circuit that will make the distortion sound nicer, IMO.

The main drawback of transistors is that they just don't look as cool as tubes ;-) It's hard to get all nostalgic over a chunk of plastic with three wires sticking out of it.

BTW, did anyone see the new Line 6 amp - with tubes? http://line6.com/spidervalve/ It seems to have the Line 6 DSP front end feeding into a tube power amp.

[xFallen]

Didn't Link Wray do the same thing to get the sound on "Rumble" a few years earlier?

http://www.youtube.com/watch?v=PP0aRKnyzpc

Yeah, damn. I haven't watched the video yet but I do seem to recall hearing that anecdote. I should know better. I have a friend who is unusually well versed in rock and roll history and constantly reminds me of the greats and the roots. We went to see Link Wray when he passed through here several years back. He rocked the house.

I'll take tubes over transistor amps any day. But it is absurd of course to eliminate individuals based on electrons flowing through silicon. So many great rock, jazz, blues and country guitarists over the years have used many tools to get sounds and styles that have made history. We all know who they are. How the term wimp applies to them is completely irrelevent and at best would be described as inflammatory a.g.a-style trolling. Big old yawn.

BB King's main squeeze is a Lab Series all transistor amp and in interviews claims he will take that over his second choice, which would be a Fender Twin. Ty Tabor of King's X, Alan Holdsworth also use or have used an L5! The list goes on. Based on the previous absurd assertion includes anyone who used a pedal in front of an amplifier. Hendrix, Clapton, May, Malmsteen, Page, Santanna, Rhoads, Vaughan...the list is extremely long.

Long live the wimps. They seem to know how to play guitar.


Barry

[clintonb]

Electar Tube 10.
It has a real limited bandwidth, it distorts too early, it sounds bland.
So that's why I modded mine!

- Clint

[csparks75]

Man, I feel really nasty now, because I LOVE my rect-o-verbs...am I just naive? Now, I do have a Studio Caliber DC-2 that I'm not so happy with...it does clean well IMO, but I can't get decent distortion from it.

I think the issue for my ears are the EL-84s there. For some reason, I can't bring myself to like my sound on overdriven EL-xx tubes. I don't understand, I love guys like Slash (Marshall), the Mr. DeLeo (VOX), etc. who play EL-xx gear, but I just can't get the sound *I* want playing on that stuff. 6L6 is something I can do all day long, but I'll be damned if I don't want to vomit when I try to play an amp with EL-xx in it....

Do I need to go to Rehab because I like Mesa gear?

Now, I'll agree with the overpriced comment....paid a boatload for a roadster 2X12 combo that I lost 600 bucks on when I sold it, when I should have converted it to a head unit....the thing weighed a TON!

[Arthur Dent]

Worst tube amp I've ever heard? Kent Trem-Tone. 12au6 in the preamp, 12av6 in the trem circuit, 50C5 power tube, used to run straight off the mains. All the tubes are weird, the trem sounds like a dieing duck, and the whole thing just basically sounds bad. Thank God I got it for free.

[mykey]

Do I need to go to Rehab because I like Mesa gear?

yes, but you would be surprised that many musicians gave up mesa boogies and went on to live normal, productive lives.

[mykey]

Worst tube amp I've ever heard? Kent Trem-Tone. 12au6 in the preamp, 12av6 in the trem circuit, 50C5 power tube, used to run straight off the mains. All the tubes are weird, the trem sounds like a dieing duck, and the whole thing just basically sounds bad. Thank God I got it for free.

put it on e bay and list it under: "vintage tube amps"
you will get $500 no problem.

aren't you the main character in "the hitch hiker's guide to the universe"?
i thought the name sounded familiar

[PRNDL]

yes, but you would be surprised that many musicians gave up mesa boogies and went on to live normal, productive lives.

From what I can tell, many people love Mesa Boogies because they have what they want, which may be tone, high gain, versatility, or the EQ.

Most of the posts against them are because they are very difficult to repair.

One elegant solution would be to rebuild the amp with an eyelet or turret board, which is fairly common with reissue or new Fenders that break. The only issues I can foresee is whether the board would fit in the chassis, if you can reuse expensive parts (relays, etc), and if anyone has a circuit board designed for this.