Tube Amp: SERVICE QUESTION ! ! !

DriftingByTheStorm

hey guys ...
i have a serious question about servicinig a tube amp.

I have had a 40watt Fender Hot Rod Delux for about 4 years...

it HAS NEVER BEEN SERVICED ...

i have let my younger friends borrow it over the years, and i know they crank the hell out of it ... one time it started to sound like shit, recently.

i suspect they screwed up the voltage or blew a tube.
or otherwise fuked the tubes up, or something.
i know shit about amp servicing.

i took my amp to the store i bought it at, Melody Music, in northern virginia. i think they are morons, and don't trust them for shit ... but they are close by.

anyway ... there are two other notcible problems with it ...

a. the red jewel light, that tells you the amp is on, is missing
b. the "sharp tone" switch hasn't worked for a LONG time

now,
the Melody Music has had this amp for TWO FUCKING MONTHS.
they finaly called me and said it was ready.

when i asked them what they did to fix it ...
the guy said "we fixed the jewel light, and other than that, it looked fine. we couldn't find anything else wrong with it."


SHOULD I SPECIFICALY HAVE TO TELL THEM TO LOOK AT THE TUBES !?! Isn't this the most fundamental, and obvious part of amp service?

shouldn't these tubes atleast have their output adjusted or "tuned" ... if not completely replaced ?

also, on a side note ... would Electro Harmonix tubes be ok in this kind of amp?

i really am not feeling confident with these morons at all.
it seems like after 2 months, they should have already changed, matched, and tuned new fucking tubes ...

goddamnit.

what should i do !?!?

(and how much should this service reasonably cost !?!)

thanks guys.

exhausted

should be due for a re-tube. definitely.EHs are good.

i'm not an expert on amps but if it's been used a lot and cranked a lot, it should been thoroughly inspected by someone who knows what they are doing.

Pacomc79

http://trentino.best.vwh.net/


Trentino has a good site.

Also check http://www.unclespot.com/amps.html

You need to change the tubes, the transformer and the caps aren't due for service yet.

Go with Electro Harmonix, you'll be pleased.



you can find tubes here http://www.thetubestore.com/

WiLL75

I don't think the tubes have ever been changed in my '73 bassman 10. About a year and a half ago I changed two speakers, as one had completely blown and the 2nd one in the chain was starting to go. There's a guy here who's amazing when it comes to anything that is tube driven, from old amps to old radios. Anyways, I haven't noticed anything wrong with my sound or anything like that...I was just thinking about picking up a whole set up tubes for when I do have to change them.

But I have no idea what brands are good and I really like the tone I get now, any reccommendations out there?

Pacomc79

Just scroll through the pages at the the tube store.

I believe the Bassman uses 6L6's. Tesla, Electro Harmonix, EI, Phillips JAN (NOS) All great tubes. If you could find some NOS RCA's that'd probably be the most authentic but you are going to pay out the ass.


For the Pre Amp 12AX7's I don't think it gets better than Electro Harmonix especially the ones with the gold pins. I currently have all EI tubes in my Orange and they sound great too.

For your reverb? (if it has reverb I can't remember) I believe a 12AT7 driver is necessary, all these companies make them too. the tubes are reviewed on the aforementioned site.

Your amp being that old is more than likely over due for a filter cap and tube socket replacement you might want to have the man check it out.

http://www.thetubestore.com/6l6review.html

WiLL75

Thank you for the advice, it is much appreciated. It doesn't have reverb, so at least I don't have to worry about that.

WiLL75

Decided to pull out a tube from the far left. It must be the original tube, it says....

6L6
GC
usa

on the glass part, then at the bottom..on black..metal I guess, in redish-orange letters...

Fender 023556 .38
APK 13
Special Design 21

I have no idea what the numbers mean.

WiLL75

do those mean anything to anybody? The numbers? What I described?

Pepe Silvia

Originally posted by WiLL75
Decided to pull out a tube from the far left. It must be the original tube, it says....

6L6

This is what you need to look for. MIG is pretty knowledgable in tubes, he helped me with mine. I accidentally deleted his pm tho. I'm not sure if the GC is that important or not. I like Electro Harmonix ones http://www.zzounds.com/item--ELH6L6EH.

If you've never changed your tubes that's what I'd do. I also want to change my speakers at some point.

I also live in Northern VA and have had such a headache trying to find a good music shop to use. All I can say is stay away from Apple Music in Fredericksburg, Music Outlet in Manassas and I think it was Alexandria Music...anyway if you find a good shop be sure to let me know.

mccreadyisgod

Originally posted by WiLL75
do those mean anything to anybody? The numbers? What I described?

The only important number there is "6L6." You get any 6L6 tube, you'll be in business. If you want to get particular, there are "hardness" numbers that indicate how much compression, saturation, and distortion you'll get. That's sort of a personal preference, though. I LOVE Electro-Harmonix tubes, for all applications... pre-amp, power-amp, rectifier...

Now, for the vintage gear, you won't get quite a vintage tone out of an E/H tube. If you want to capitalize on the vibe, stick with Groove Tubes, Ruby Tubes, or find someone with NOS Phillips tubes. I run E/H in my 1965 Fender Vibro Champ, but I still use a NOS GE rectifier (nobody makes a 5Y3 these days). You could go Russian, either Sovtek or Svetlana... I don't mind Sovtek, but I'd never personally use a Svetlana. I'd mention Mullards, but that doesn't help with a Fender amp.

Now, your Bassman 10 amp uses two 6L6 power tubes, and two 7025 preamp tubes. Nobody makes a 7025 tube anymore, but that's because they basically relabeled them 12AX7 tubes. So look for 12AX7's instead. Actually, it's a whole family of tubes... in the format of 12A_7. There are 12AX7's, 12AT7's, 12AU7's... it goes on and on. 12AX7's are the most common, though... 12AT7's are great phase-inverters or reverb/tremolo tubes, or mellower preamp tubes. You also have a solid-state rectifier, so no tube to worry about there.

Pepe Silvia

Originally posted by mccreadyisgod
Actually, it's a whole family of tubes... in the format of 12A_7. There are 12AX7's, 12AT7's, 12AU7's... it goes on and on. 12AX7's are the most common, though... 12AT7's are great phase-inverters or reverb/tremolo tubes, or mellower preamp tubes. You also have a solid-state rectifier, so no tube to worry about there.

Interesting. So what if an amp doesn't have any phase or reverb/tremolo? Would using a T7 be any different than using a X7?

mccreadyisgod

Originally posted by GlorifiedG
Interesting. So what if an amp doesn't have any phase or reverb/tremolo? Would using a T7 be any different than using a X7?

Well, you can use any of that family of tubes in that position, but a 12AX7 gives the best gain characteristic. If you want to mellow out a harsh amp, then you can swap in a T7 or a U7, and have pretty good results, or in a pinch it will work. But generally, I'd stick with the X7.

WiLL75

Originally posted by mccreadyisgod
The only important number there is "6L6." You get any 6L6 tube, you'll be in business. If you want to get particular, there are "hardness" numbers that indicate how much compression, saturation, and distortion you'll get. That's sort of a personal preference, though. I LOVE Electro-Harmonix tubes, for all applications... pre-amp, power-amp, rectifier...

Now, for the vintage gear, you won't get quite a vintage tone out of an E/H tube. If you want to capitalize on the vibe, stick with Groove Tubes, Ruby Tubes, or find someone with NOS Phillips tubes. I run E/H in my 1965 Fender Vibro Champ, but I still use a NOS GE rectifier (nobody makes a 5Y3 these days). You could go Russian, either Sovtek or Svetlana... I don't mind Sovtek, but I'd never personally use a Svetlana. I'd mention Mullards, but that doesn't help with a Fender amp.

So if I go Groove Tubes for the two 6l6's, I should also stick with them for the two 12ax7's? I don't really know if I'm hearing how this amp sounded like back in '73...as the tubes are original but past their prime...all I know is that I love how clean the tone is. So if groove tubes will get me a cleaner tone, I'll go with them.

Pacomc79

Originally posted by mccreadyisgod
The only important number there is "6L6." You get any 6L6 tube, you'll be in business. If you want to get particular, there are "hardness" numbers that indicate how much compression, saturation, and distortion you'll get. That's sort of a personal preference, though. I LOVE Electro-Harmonix tubes, for all applications... pre-amp, power-amp, rectifier...

Now, for the vintage gear, you won't get quite a vintage tone out of an E/H tube. If you want to capitalize on the vibe, stick with Groove Tubes, Ruby Tubes, or find someone with NOS Phillips tubes. I run E/H in my 1965 Fender Vibro Champ, but I still use a NOS GE rectifier (nobody makes a 5Y3 these days). You could go Russian, either Sovtek or Svetlana... I don't mind Sovtek, but I'd never personally use a Svetlana. I'd mention Mullards, but that doesn't help with a Fender amp.

Now, your Bassman 10 amp uses two 6L6 power tubes, and two 7025 preamp tubes. Nobody makes a 7025 tube anymore, but that's because they basically relabeled them 12AX7 tubes. So look for 12AX7's instead. Actually, it's a whole family of tubes... in the format of 12A_7. There are 12AX7's, 12AT7's, 12AU7's... it goes on and on. 12AX7's are the most common, though... 12AT7's are great phase-inverters or reverb/tremolo tubes, or mellower preamp tubes. You also have a solid-state rectifier, so no tube to worry about there.

The EH's are modelled after RCA 6L6's that fender used in the old days. As are the SED 6L6's

If you have some change try the Phillips NOS or Sylvanias.

http://www.thetubestore.com

The EH EL-34's are aparently pretty good Mullard EL-34 copies but don't tell that to someone who just spend $200 retubing thier DR 103

Go with EH preamp tubes they are as good as they get.


Ruby tubes sound good though if you'd like to hear some Hughes and Ketter amps come stock with Ruby tubes.

New Orange Amps come stock with EI's.



Tesla (JJ) and Sovtek are favorites of many other players

http://www.rubytubes.com

Pepe Silvia

Originally posted by Pacomc79
The EH's are modelled after RCA 6L6's that fender used in the old days. As are the SED 6L6's

If you have some change try the Phillips NOS or Sylvanias.

http://www.thetubestore.com

granted I didn't search in depth but the only phillips or sylvania ones I found there were pre amp and not 6L6's

Pacomc79

Originally posted by GlorifiedG
granted I didn't search in depth but the only phillips or sylvania ones I found there were pre amp and not 6L6's

GO to the top of the page and click on 6L6

http://www.thetubestore.com/ehx6l6gc.html

WiLL75

Originally posted by Pacomc79
The EH's are modelled after RCA 6L6's that fender used in the old days. As are the SED 6L6's

If you have some change try the Phillips NOS or Sylvanias.

http://www.thetubestore.com

The EH EL-34's are aparently pretty good Mullard EL-34 copies but don't tell that to someone who just spend $200 retubing thier DR 103

Go with EH preamp tubes they are as good as they get.

Ok, so you're saying go with the EH for all the tubes as they will come close to the original sound. The more expensive Phillips and Sylvania NOS ones will come that much closer then. Hhmmm...decisions, decisions.

WiLL75

Right now it's looking like the EH 6L6GC with the EH 12AX7EH.

http://www.westernwireless.ca/

That's the guy who rewired my speakers and who will be checking out my amp, if he ever emails back soon. I should just call. But anyways...

mccreadyisgod

Well, now, a lot of new questions...

I wasn't aware of EH tubes being designed with a new vintage-vibe value... in my experience, EH tubes seem to drive a bit more, get a bit gritty. Of course, a lot of those older tubes were pretty gritty, too. Anyways...

You can mix-and-match, whatever tubes in whatever position from whatever manufacturer, with one big exception: Whichever power tubes you get, get a matched duet (where both tubes match each other) so that your amp will work most efficiently. It will prevent problems in the long run, and will greatly increase your amp's lifespan and efficiency. Other than that, you can mix up all of the preamp tubes, and none of the preamp tubes has to match the power tubes, either.

There are a lot of options in the tube world, and there are positives and negatives for almost any option. I personally prefer to have all my tubes (pre and power) match, from the same manufacturer (EH) but that's a personal preference, not a necessity.

WiLL75

Yeah, I knew I had to have them matched, but other than that I didn't know the differences in brands and such...which is why I'm appreciating all the advice...

Pacomc79

Mig that's for the 6L6's. The EL-34's are decidedly more edgy and more like mullards which I can only assume is loud clean and chimey like a DR 504.

The 12ax7's are very nice for high gain and or sound more modern.

If you look at some old RCA's in the back of middle 60's Fender amps the EH 6L6's look very similar.


some other prices. I hear the gold pins are very nice.

Basically what it comes down to is use whatever tubes you want. Read reviews whatever. Generally though I think the Electro Harmonix tube are held in very high regard.

Older tubes like Phillips Sylvania and RCA are just NOS and generally since the technology hasn't changed there new and old as long as you build it the same way is essentially the same thing.



Just as with any light bulb some are simply built better than others. You just have to look at quality.

Tesla (JJ), Electro Harmonix. Ruby, and EI are the most highly regarded modern tubes.

Sovtek makes some good stuff and some bad stuff but they are by far the most common

Groove Tubes are used in virtually well ok all fender amps in the last I don't know how many years.

Mesa Boogie has their own brand too if you'd like to try them.

http://www.mesaboogie.com

WiLL75

I checked out the ruby tubes...they sound like they are pretty good tubes...from what I've read..which really isn't that much...

WiLL75

Well, this friend of mine who runs a music shop here (we have two, one is mainy piano's, this one is mainly guitar, bass, some percussion, dj stuff...) and they recently got a tech guy to do repairs. My friend told me he knows his stuff, so I brought my amp in to do the once over, see if the caps or anything else needed replacing. He can get groove tubes. So I'm going with groove tubes. I wonder if I'll hear the difference between 31 year old tubes and groove tubes? ; ) Anyways, when the new ones need replacing, I'm gonna give EH a try. Compare.

Pacomc79

they should sound better because they aren't used up.

Groove tubes are fine. They are used in everything, but most notably all new fender amps.


The Groove Tube Amps are outstanding.