tremoverb help

[tremoverb nick]

Hiya folks

I've been using a tremoverb combo since the early 90's and recently noticed a kind of "lag" or delay - esp on the red channel.

Whether at home or at gigs - with no fx at all - it's like there's a delay or a slowness tracking my notes.

I haven't had a single problem with this amp and can't for the life of me work out what the prob is.

I've tried changing power tubes - no change.
I used quality dimarzio leads.

The only thing I haven't tried yet is the preamp tubes..currently i've got groove tubes in it.

Please can anyone help!!!

 

[stephen sawall]

Do you have the reverb on ?

 

[tremoverb nick]

No - well, either the reverb is totally off or there's a teeny bit of reverb.

 

[domct203]

Are you using Diode or Tube rectifiers? If you are using the Tube rectifiers, switch over to Diode and see if things improve.

Do you have the reverb on ?

I don't understand why that would matter, we're not talking switching lag here right?

Dom

 

[tremoverb nick]

Silicon diode rectification.
My local amp tech has advised buying one new preamp tube...an electro harmonix..and trying it one socket at a time. I know my output valves are fine cos I've tried two different sets and the fault persists.

He also suggested that because I've been playing thru a 1964 ac30 I've gotten used to faster more responsive attack...

I'm not sure bout that...the t-verb has always been awesome..I'd have noticed it.

 

[domct203]

Well, don't leave that Electro-Harmonix in V3 or V4, those are cathode follower positions and the EH has been known to fail there. A much better choice would have been the Penta or GT Chinese.

Read here for more info on this.
http://forum.grailtone.com/viewtopic.php?f=4&t=25102&start=19/

I guess your tech didn't get the memo, or is not a Mesa Certified tech.

Dom

 

[94Tremoverb]

The filter caps might be on the way out too - early 90s is getting long enough ago for that to be a possibility, especially if the amp has sat unused for a while. Decaying filter caps *can* sound like the amp is 'slowing down' too.

A filter cap job is inevitable at some point in the life of an amp, and it's probably worth doing at about 20 years old if you feel the amp isn't performing as well as it should. Many amps go thirty or forty years on a set of caps and seem to sound fine (in fact if you love the sound there's no real reason to change them until about that sort of age), until you change them and hear just how much snappier and more responsive they are with the new ones.

 

[TremoJem]

Wow, filter caps.

Never heard that one before.

Elaborate if you will. I like hearing anything I can about components used in amps.

If you did not share this great information then most of us would be clueless.

 

[94Tremoverb]

Wow, filter caps.

Never heard that one before.

Really?!!

They are one of the main maintenance items on any older amp. Very common knowledge that they need replacing every 20-40 years - I'm surprised you haven't heard of this.

Elaborate if you will. I like hearing anything I can about components used in amps.

Filter caps are electrolytic capacitors, they store charge in the power supply. The technology is somewhere between a normal cap and a rechargeable battery - the charge is stored chemically. As they get old, the electrolyte becomes degraded and doesn't hold charge as well, and its internal resistance rises - exactly like what happens to a lead-acid car battery. This is sometimes called "drying out". They perform less well and can sometimes fail, either open-circuit causing either a loud hum or odd oscillation problems (and no damage) or short and blow fuses or in serious cases, take out other parts up to the power transformer (this is very rare, but possible if the wrong fuse has been fitted).

Like a lot of things, they usually don't fail suddenly but degrade slowly so you don't really notice. Opinions vary on when they should be changed routinely from 10 years (which I think is ridiculous) up to "leave them alone if they haven't failed" (which I think can be risky). Some people actually like the tone old caps give. I tend to think about 40 years is a good upper limit, unless you've noticed that the amp isn't sounding as good, or if other major service work is needed in which case I would bring it forward to about 20 years. Modern caps generally last better than vintage ones too.

There are a few other electrolytic caps in an amp, typically in the bias supply (these should be changed as well, since if they fail they will take out the power tubes) and cathode bypass caps for various tube stages - I don't normally change these unless they've drifted well away from the correct value. In a modern channel-switching amp like a Mesa there will be some in the low-voltage supply as well, I would leave these unless they've failed since they don't affect the tone, or reliability to any major extent.

Don't change any of the non-electrolytic caps unless they've failed - there's no need and the ones in the signal path will affect the tone.

 

[TremoJem]

Great post and very useful information.

According to Mesa, I have a 2000 and a 2001 Tremoverb.

I should not have any problems.

My effects are now in order so all in all I am good to go for now.

Having read your post, I now have a little more ammo in my troubleshooting arsenal for any future problems.

Thanks again.

 

[tremoverb nick]

update -

So, rehearsed tonight.
There's undoubtably a natural reverb / echo in the room.
Nonetheless - i'm kindof listening out for the amps "delay".
Tonight i cranked the amp and although i could hear the delay, the bass player thinks that it's the room.
I gave it a bit more gain/master and the sound became more "immediate" and i thought i'd solved the delay issue.
Then....i noticed that it was where i was standing..in front of the amp - no delay...to the side - delay.

surely it's the room...

aaargh!! this is messing with my mind!!!

I also played with the bold/spongy settings - no difference there regarding delay.

I've gotta feeling it's me just being a dick! - the amp is fine.

Should any of you fine fellas live in south wales uk - and have a tremoverb combo..please let me know - maybe we could get together and compare.

what's your thoughts on this delay/ears problem?

 

[stephen sawall]

Do you have the reverb on ?

I don't understand why that would matter, we're not talking switching lag here right?

Dom

:?: :arrow: Just my style of a bump. Just like this post....
Interesting thread so far ...

 

[tremoverb nick]

the 12ax7eh arrived.

Mangaged to find some "me" time without wife and kids.

got ready for some serious a/b testing.

Noticed v6 was missing!!!!!!!

so..i took all the groovetube 12ax7m tubes out.
put an old spax7 in v1, brand new 12ax7eh (cryotested), some old sovtec 12ax7wb's in v3 v4, and groove tube 12ax7m's in v5 and v6..

My sound is back!

full - big, immediate.

big bottom end etc.

awesome!!!!!

 

[stephen sawall]

......

 

[94Tremoverb]

Noticed v6 was missing!!!!!!!

If V6 was missing the amp wouldn't work at all. That's the phase inverter. The only preamp tube that can be missing and the amp still work is V4, which is the FX loop tube - and only if the loop is not selected.

so..i took all the groovetube 12ax7m tubes out.
put an old spax7 in v1, brand new 12ax7eh (cryotested), some old sovtec 12ax7wb's in v3 v4, and groove tube 12ax7m's in v5 and v6..

If you really have put Sovteks in V3 and V4, you're best to take them out again before they fail. Those are the cathode-follower positions and Russian-made 12AX7s don't hold up well in them.

V1 - first tube from the input jack in the front row (looking at the amp from the back) under the metal cover. V2-V4 - other tubes in the front row, in order from V1. V5 - tube nearest the rectifier tubes in the back row; V6 - tube nearest the input jack in the back row, roughly in between the two middle power tubes.

(Edit: stupidly, while trying to clarify V5 and V6, I listed them the wrong way round. Doh! Sorry . V5 is definitely the one nearest the rectifier tubes.)

 

[domct203]

Don't use any New Sensor Corp Russian 12AX7 tubes in V3 or V4 fo the reasons mentioned by 94tremoverb. New Sensor brands include Sovtek, Electro-Harmonix & Tung-Sol reissues. New Sensor also makes the Mullard reissue, so I would not use them either to be safe.

Tubes that have been proven to hold up in cathode follower spots are the JJ (current Mesa 12AX7), any Chinese (Shuguang/Penta, Mesa "Chinese", GT 12AX7-C) and just about any NOS.

Do not use ANY BRAND of 12AT7 as these are not even designed to withstand the voltages of Cathode Follower positions.

Dom

 

[tremoverb nick]

Great info..folks ...many.thanks.
I swear its been without v5 or v6 (have to look to remember) and working.

I must've bought the groovetubes (back in 2004 when it was last retubed) and bought 5 instead of 6.I'm just glad its sounding the way I remember it. I kindof retired in to the acoustic world a while back....since then hardly used the t-verb.

 

[94Tremoverb]

I swear its been without v5 or v6 (have to look to remember) and working.

That really isn't possible . But without V4, certainly - if you don't use the FX loop. Removing either V5 or V6 *will* stop the amp working - unless you're plugging your signal into the FX Return jack instead of going through the preamp, when it would in fact operate without V5 (but not without V4 or V6).

 

[tremoverb nick]

Well.. either way, I rehearsed last night and the amp is back the way I remember it.

I really was wondering if my ears/playing had changed...so I'm glad that it was the amp - not me.

Now it's all up and running - i can start tinkering with various preamp tubes -

for the record - i've been using 2xel34s, 1 rectifier tube.
along with the preamp tubes mentioned earlier.

Do any of you fine fellas have a recommended line up of preamp tubes?

cheers

Nick

 

[stephen sawall]

I use mesa preamp tubes I bought in the 80's and 6CA7 I got about the same time. I bought a lot of tubes when the quality of tubes started going down hill around 90.