Low Power Tube Amps

[Dave da Dude]

I was lookin' 'round the Fab site some more.

 

The Scamp looks cool too ... and only $250 each Get one in "British" (Vox AC4) and one in "American" (Fender Champ)

 

The GAS is getting too much to bear

[LPCustom]

Well, the V8 went back to GC today and I got a refund. I'm still trying to get a schematic for the V58 to see if it has op-amps or not.

 

I'm also poking around on eBay looking for older lower powered tube amps. Some of the old Bogens look kind of interesting but most were, I think, 10 watts or more.

 

I'm still thinking of building my own from a schematic.

 

Amazing the amount of crap you have to wade through on eBay when searching for "tube amp". About 90% of what you find isn't tube amps but tubes and other stuff. By the time I get a decent search, I've got 35 keywords excluded. The same is true when searching for Fender Strats or Teles. Sigh...

[LPCustom]

I finally got a schematic, layout and parts list for the Crate V58/V8 (they are the same amp section) today.

 

The pre-amp still has the TL072 dual op-amp in the gain stage. So I won't be buying a V58.

 

One interesting bit. The original V58s were the same as the V508 just with a different cabinet. They only revised the circuit board on the last run and did not remove the op-amps from the design.

 

I emailed them back and thanked them for the schematic and told them that I would ont be buying one of the V58 amps because it has the op-amps in the pre-amp.

 

Hopefully they will realize that they are losing sales because of that design decision and perhaps change the design or come out with a new model that is all tubes.

[comacoda]

I play an Epiphone Valve Special and Goldtone ga15rv. Usually ab'em and play them at the same time with or without effects. Right now I'm using verb with 5 dirty watts of VS and 6 clean watts of Goldtone.

[Laurie LaCross-Wright]

We have been looking for a couple small tube amps but haven't come across anything that really kicks us in the shins and hollers "BUY ME!"

 

We could have cried when we heard that Joe Naylor from Reverend discontinued the Hellhound. What a cool little tube amp - at 50W I guess it ain't so little though, although it is portable. Rusty just connects it to a 2 - 12 cab for larger shows. We have a Kingsnake too but like the Hellhound better.

Laurie LaCross-Wright

[Steevo]

I've been following this, and other, low-power, class A tube discussions for awhile. I just got a 1965 Blackface Fender Champ to play with. I really wanted to like it. I don't. The 'creamy' distortion I was told about does not exist. And I'm hitting it with the '57 classic humbuckers in my Gibson 356. My Boss GT-6 multi effects processor sounds so much better. Maybe this old Champ needs some TLC, but at this point there is nothing musical about this amp. What am I doing wrong?

[BillWelcome Home Studios]

I didn't care for the blackface or silverface Champs either. I thought that it was just me. Seemed flat and lifeless, though my '52 Champion 600 (older brother to the Champ...) sounds great..

 

Hey, have you looked at ax84?

 

But I still have a bunch of old, low power tube amps that sound very nice indeed. (I sold some of them) I still think that the UniValve trumps them, but they are all individual sounding pieces, and each has a use.

 

Bill

[Steevo]

Hi bill, I don't know what ax84 is. I've been playing long enough that I should be more of a 'vintage' guy, but I guess I'm not. Flat and lifeless pretty much describes this thing ... you've been around the block a few times haven't you?

[BillWelcome Home Studios]

Originally posted by Steevo:

Hi bill, I don't know what ax84 is. I've been playing long enough that I should be more of a 'vintage' guy, but I guess I'm not. Flat and lifeless pretty much describes this thing ... you've been around the block a few times haven't you?

There was a time when I either bought everything or got to audition everything. So when we are talking about stuff from the late 1960s (which I would find used...) or 70s or early 80s, I've probably owned one.

 

I've got a different attitude now. I just want to have a couple of nice things, rather than own everything ever made.

 

 

Bill

[LPCustom]

Well those old vintage amps do get a little tired over the years. I have a friend who bought an early 60s (pre CBS) Champ last year and it sounded pretty cruddy when he bought it. After replacing the tubes and the caps in it, it sounds pretty good. The old driver in it is tired, too, I think. It sounds even better hooked to an external 1x12 cab with an Eminence speaker in it (Blue Coat, I think).

 

So if you buy a vintage amp (especially pre-60s), unless someone else has done the work of renevating it, it probably needs it by now.

 

After hearing the before and after on my friend's amp, I can safely say that it can make a huge difference in the tone.

[The Geoff]

bump

[BillWelcome Home Studios]

That could all be true, but when I bought my Champ in 1972, it was a 1972 Champ that was flat and lifeless.

 

Bill

[LPCustom]

Originally posted by bpark@prorec.com:

That could all be true, but when I bought my Champ in 1972, it was a 1972 Champ that was flat and lifeless.

 

Bill

Well, I guess you can't do much with that, then.

 

I wonder what differences there are (if any) between the '72 Champ and the Pre-CBS Champs?

[Caevan O’Shite]

[Juan Alberto Hoya]

What about this idea: This is for the techies.

 

1-get a 1 Watt tube output circuit schematics (this is dead easy to put together as there are only 5/8 components). Mount it in a circit board.

2-install a switch in your favorite amp to route the preamp signal to it.

3- attach 1 inside your amp, apply power from the DC of your amp reducing it with a resistor accordingly and...you should be laughing!

 

The main question if you are capable of this is... which 1 watt circuit would sound best.

[Basshappi]

Lots of cool info here.

[LPCustom]

Originally posted by Steevo:

I've been following this, and other, low-power, class A tube discussions for awhile. I just got a 1965 Blackface Fender Champ to play with. I really wanted to like it. I don't. The 'creamy' distortion I was told about does not exist. And I'm hitting it with the '57 classic humbuckers in my Gibson 356. My Boss GT-6 multi effects processor sounds so much better. Maybe this old Champ needs some TLC, but at this point there is nothing musical about this amp. What am I doing wrong?

Hey Steevo. Whatever happened with your Blackface Champ? Do you still have it? Did you ever get the tone you wanted?

[Bbach1]

Originally posted by Ricochet:

5W isn't really a small amp. Crank it up and it's LOUD!

I don't feel it's about loudness. They are all loud. I think it's about headroom. I like my amps powerfull for the headroom and being able to drive whatever cabs I want. The downside of course is that you really have to get loud to really get the amp to strut its stuff.

[BadLife]

LPCustom what is the op-amp ???

 

The pre-amp still has the TL072 dual op-amp in the gain stage.

 

What does this do to make it sound bad? I was looking at the V8 or whatever it is and also the little Epi but I could not really tell much about them form looking. Is the Crate a Class A or A/B? I thought the Epi was supposed to be Class A.

[BadLife]

Is the TL072 dual op-amp a fuzz chip?

[Mr. Slotty]

Hi,I want to mod an Ibanez Valve Bee...already managed to convert it to an el34,but there are a couple more things I want to try and need the schematic.

 

At Ibanez they are totally useless...I asked for a schematic after buying the amp,gave them the serial number,told them I badly need the schematic because I want to repair the amp,and they told me basically 'no,the schematic is not supposed to be given to the general public!'

 

Am I 'general public'...I am a customer! what a bunch of clowns. I will never buy anything again with Ibanez written on it...their customer service is rubbish.

Anyway sorry for the rant....if anyone has the schematic,although I doubt it,I would be very grateful

[Ricochet]

Originally posted by Bbach of Bismarck:

I don't feel it's about loudness. They are all loud. I think it's about headroom.

It's funny, on various boards when these discussions come up, mostly either folks want to run their amps in "output tube saturation" all the time, thinking there can be no other way to achieve a tone that's tolerable, or else they want lots of clean headroom. Definitely different clienteles. And there's yet another group that likes the "touch sensitivity" of an amp that's running clean with soft playing and starts to "crunch" when played louder.

 

Different strokes for different folks.

 

Personally, I like smallish amps run in that middle ground on the edge of distortion, but most of the time I'm playing at low volume and therefore "clean."

[LPCustom]

Originally posted by BadLife:

LPCustom what is the op-amp ???

 

The pre-amp still has the TL072 dual op-amp in the gain stage.

 

What does this do to make it sound bad? I was looking at the V8 or whatever it is and also the little Epi but I could not really tell much about them form looking. Is the Crate a Class A or A/B? I thought the Epi was supposed to be Class A.

Well, op-amps are type of solid state electronics. It's short for "operational amplifier". Basically it's an integrated circuit. All it does is amplifies the voltage in a signal circuit (most are pretty high gain).

 

Solid state electronics generally yield a more harsh or "brittle" sound when used in guitar amplifiers. The TL072 op-amp does exactly that to the sound of the Crate amps they use it in, IMHO.

[LPCustom]

Originally posted by Ricochet:

Originally posted by Bbach of Bismarck:

I don't feel it's about loudness. They are all loud. I think it's about headroom.

It's funny, on various boards when these discussions come up, mostly either folks want to run their amps in "output tube saturation" all the time, thinking there can be no other way to achieve a tone that's tolerable, or else they want lots of clean headroom. Definitely different clienteles. And there's yet another group that likes the "touch sensitivity" of an amp that's running clean with soft playing and starts to "crunch" when played louder.

 

Different strokes for different folks.

 

Personally, I like smallish amps run in that middle ground on the edge of distortion, but most of the time I'm playing at low volume and therefore "clean."

Funny you should mention that, Ricochet. KBP (now HardTail) and I were chatting about that last evening a bit.

 

I, too, like to play at just under the distortion so I can get it to crunch by changing my attack. That's usually on my Tele or Strat, though. And usually not very quiet.

 

I don't usually play all that loud when I play clean (no crunch). So lots of headroom doesn't matter all that much to me on my practice amp. Playing clean on stage, though, is a different matter. But, I have a big rig for that.

 

When I'm playing at fairly low volume, I either like it pure clean (well maybe some reverb and/or delay) or pretty overdriven.

[Verne Andru]

I thought I'd chime in a bit about the Crate V8 if anyone is interested. I've been looking for a small watt tube amp for recording for some time and finally decided on the V8 for a number of reasons:

 

1] It's made by St. Louis Music, the same people who make Ampeg. The only thing "Crate" about it is the name on the back of the amp. Everything is SLM stamped from PCB to transformers to the manual. I have not a/b'ed the schematics, but my hunch is that it's an update from the old Ampeg 5 watters. It's an Ampeg in Crates clothing.

 

2] It's MIA [until LOUD moves everything to Vietnam next year] and is very well built.

 

3] It has a 10" Celestion speaker - most others in this class have 8's and I've yet to hear an 8" that doesn't sound like a shoe box.

 

4] Most important, it has an FX loop.

 

As LPCustom notes, the V8 uses a TL072CN opamp for the first stage of pre-amplification. As another tech noted, theoretically this is quite smart because tubes - especially in the primary pramp stages - add significant noise to the signal that gets passed along. The problem with the V8 is the TL072CN is a cheap opamp that's just as noisy as using a tube so you don't really gain much from the design until you change opamps. I replaced the TL072CN with a TLE2072. This is one of Texas Instruments Excaliber series and is reknown for being the best of the best. All the hiss and other noise disappeared and I gained between 20 and 30% more clean headroom. TL072CN's sell for around 20 cents. The TLE2072 from Mouser is around $2.50. The only hassle with changing opamps is they didn't use a socket so you have to do a bit of board surgery. It took me around 10 minutes to remove the old chip, solder in a socket and plug in the new chip. It's the best upgrade you can do and it costs less than $3.00 including socket and solder.

 

Where the V8 really shines is when you use the FX loop properly. The volume knob is really an FX send level control. When maxed it approximates an instrument level signal so you can use it with other FX. The EL84 is running wide open all the time just shy of distortion so without FX all the distortion is coming from the preamp gain stage. When you put a clean booster in the FX loop and start pushing the signal going back into the amp closer to line level, you start driving the EL84 into distortion which is far darker and creamier than the pre-amp distortion. This lets you tailor the distortion between pre and power tubes to taste - something that's impossible to do without the FX loop.

 

One of the really neat things you can do with a low-watt amp is to add a master volume control AFTER the power amp. I built a backpack box that bolts to the back of the amp that contains an L-pad - a big volume control you normally find in-wall for remote controlling the volume of a stereo system. They cost under $10 at an electronics store and are designed to keep a constant load on the amp while allowing you to control the volume going to the speaker. And it doesn't suck tone like the expensive attenuators do - it's totally transparent. With it I can keep both the pre and power sections maxed so I'm getting the distortion I want, yet I can turn the volume down to a whisper. I also did an DI circuit that's all of 2 resistors so I can plug the V8 into a higher power amp for gigging or into my desk for recording.

 

It's a killer little amp and well worth looking at. There are others coming into this market and I expect things will heat up in the near future. Peavey is getting aggressive with their low-watters, but they've not come up with the ONE yet, IMO. The JSX is close, but the 8" speaker [should be a 10] and tremolo [should have been a reverb] were rather silly decisions that stop it from being the one to beat. From what I've seen so far, the V8 with the few mods I mentioned above, is the best in the field so far. Hope this helps - Verne

[Verne Andru]

I thought I'd chime in a bit about the Crate V8 if anyone is interested. I've been looking for a small watt tube amp for recording for some time and finally decided on the V8 for a number of reasons:

 

1] It's made by St. Louis Music, the same people who make Ampeg. The only thing "Crate" about it is the name on the back of the amp. Everything is SLM stamped from PCB to transformers to the manual. I have not a/b'ed the schematics, but my hunch is that it's an update from the old Ampeg 5 watters. It's an Ampeg in Crates clothing.

 

2] It's MIA [until LOUD moves everything to Vietnam next year] and is very well built.

 

3] It has a 10" Celestion speaker - most others in this class have 8's and I've yet to hear an 8" that doesn't sound like a shoe box.

 

4] Most important, it has an FX loop.

 

As LPCustom notes, the V8 uses a TL072CN opamp for the first stage of pre-amplification. As another tech noted, theoretically this is quite smart because tubes - especially in the primary pramp stages - add significant noise to the signal that gets passed along. The problem with the V8 is the TL072CN is a cheap opamp that's just as noisy as using a tube so you don't really gain much from the design until you change opamps. I replaced the TL072CN with a TLE2072. This is one of Texas Instruments Excaliber series and is reknown for being the best of the best. All the hiss and other noise disappeared and I gained between 20 and 30% more clean headroom. TL072CN's sell for around 20 cents. The TLE2072 from Mouser is around $2.50. The only hassle with changing opamps is they didn't use a socket so you have to do a bit of board surgery. It took me around 10 minutes to remove the old chip, solder in a socket and plug in the new chip. It's the best upgrade you can do and it costs less than $3.00 including socket and solder.

 

Where the V8 really shines is when you use the FX loop properly. The volume knob is really an FX send level control. When maxed it approximates an instrument level signal so you can use it with other FX. The EL84 is running wide open all the time just shy of distortion so without FX all the distortion is coming from the preamp gain stage. When you put a clean booster in the FX loop and start pushing the signal going back into the amp closer to line level, you start driving the EL84 into distortion which is far darker and creamier than the pre-amp distortion. This lets you tailor the distortion between pre and power tubes to taste - something that's impossible to do without the FX loop.

 

One of the really neat things you can do with a low-watt amp is to add a master volume control AFTER the power amp. I built a backpack box that bolts to the back of the amp that contains an L-pad - a big volume control you normally find in-wall for remote controlling the volume of a stereo system. They cost under $10 at an electronics store and are designed to keep a constant load on the amp while allowing you to control the volume going to the speaker. And it doesn't suck tone like the expensive attenuators do - it's totally transparent. With it I can keep both the pre and power sections maxed so I'm getting the distortion I want, yet I can turn the volume down to a whisper. I also did an DI circuit that's all of 2 resistors so I can plug the V8 into a higher power amp for gigging or into my desk for recording.

 

It's a killer little amp and well worth looking at. There are others coming into this market and I expect things will heat up in the near future. Peavey is getting aggressive with their low-watters, but they've not come up with the ONE yet, IMO. The JSX is close, but the 8" speaker [should be a 10] and tremolo [should have been a reverb] were rather silly decisions that stop it from being the one to beat. From what I've seen so far, the V8 with the few mods I mentioned above, is the best in the field so far. Hope this helps - Verne

[Warthog]

Boy oh, boy! How did this post not fall off the server after 9 months of neglect?? And how'd you find it again? I never look past page 2 and it doesn't take but a week for posts to fall to page 3...

 

Thanks for the info though!

[Warthog]

Oh, and welcome to the forum...

[mdrs]

I was just reading thru this thread, since it was resurected! I thought I'd chime in with a couple of comments about small amps.

 

I own four Champs, and consider them my favorite small amps.

 

I have two tweed Champs....both are chimey and sweet at low volume. One is a bit more distorted than the other. Both rock when cranked.

 

Perhaps my favorite amps overall (and I have a pretty decent collection of mostly old amps) are my two Blackface Champs...both made in April of 1965. I bought one, and absolutely fell in love. I liked it so much, that when I came across another made in April of 1965 I HAD to buy it too ("OD" on the label inside the cab). The blackface champs are more chimey even than the tweed champs....they can almost sound chorus like. If you turn up the volume of your guitar, or amp it'll give really really nice distortion.

 

I've noted that some humbuckers can "overwhelm" the champs, and sound lousy. Not all humbuckers do this, but some just don't sound good thru these Champs. My champs really seem to like single coil pu's better.

 

Now, IF you can get your hands on a '50 Tele or Strat, and a '50's Deluxe tweed, or Champ.....you've got a match made in heaven.....

 

Pure Chimey Fender bliss!!

 

And, I can play my Champs at night in my living room, and not wake anyone up...and it sounds really nice at these low dB levels.

[Verne Andru]

Thanks. Sorry about the double-post BTW.

 

I was looking for any information about how the V8 is biased and Google dredged up this thread. I'm going to swap out the 12ax7 for a 12at7 for another 20-30% of clean headroom and wanted to see if the V8 was fixed biased or not. I realize this thread is a tad old, but thought I'd set the record a bit straighter on the op-amp thang.

 

Thing is, hardly anybody knows about TI's Excalibur line of chips yet they are absolutely stunning and make a huge difference to your gear. I first found out about them from Richard McClish [RMC] when I was trying to get rid of the hiss in my Godin Multiac - they worked miracles. A few years back I picked up a Digitech RDS6500 rack reverb off the bay for $30 and found it had so much noise it was unusable. I swapped the opamps for a couple of TLE's and it's one of the best sounding verb's I've heard - and a bargain at $30. They are a stunning little chip and turn the V8 from a ho-hum little amp into a really tone monster. Op-amps themselves are not the problem, as long as you're using the right opamp.