Anyone know what's wrong with my amp?

[soundchaser59]

I, too, have settled on Tung Sol tubes. But my amp called for Svetlana power tubes, and I found a pair, so I bought them. I agree with the tube sentiments expressed above.

Yup, if that's a 1968 amp, that's 45 years old. It's definitely a good thing to have a tech go over it (if he's good, like Lt said). I would never take anybody's word for it if I bought something that old. I would just assume that it would go straight to the tech as soon as I put my choice of new tubes in it. Same way for used cars, straight to the mechanic for all new rubber, etc., no matter what the seller claims was done.

I'm surprised anybody would replace a tranny on an amp like that, and not get the other stuff done at the same time. I guess I've been lucky. I have a '65 Champ and all I've ever done is replace tubes. I wish I could do side by side compare, what it sounded like when I got it in '73, and what it sounds like now. It probably is a bit diminished. I've thought about sending it (the chassis) to Frenzel for a rejuvenation!

 

[Seeker of Rock]

Ok. Couple quick quesses.

1. For new tubes (JJs, Groove Tubes etc) Russian is considered better than Chinese right?

2. Is there anything to the NOS glass myth? And if so, where would I notice the difference more? With the power tubes or pre-amp tubes? Thanks.

Groove Tubes, for the most part (see below), is a tube relabeler. The actual manufacturer may be Chinese or Russian. I have Russian Sovteks labeled as Groove Tubes in my Fender, but I just bought a new set of GT 6L6-GE for it that are made (many of the parts, anyway) on the old GE dies (brought from KY to CA) but finished up in China. Generally, NOS tubes were made better and last longer but are really overpriced.

 

[Lt. Bob]

Generally, NOS tubes were made better and last longer but are really overpriced.

way over priced.
And, personally, I don't see the point.
Yes, they can sound different but 95% of the time it's not a huge difference. Every once in a while you'll run acroos one that makes a significant difference, especially with the preamp tubes. But in general I don't think they're anywhere near worth the price.
I've always thought of tube rolling as being for bedroom guitarists that sit around obsessing over tiny tone issues but don't really play that much.
Or big time players that can afford to go thru a buncha expensive tubes looking for those few special ones.

 

[Seeker of Rock]

way over priced.
And, personally, I don't see the point.
Yes, they can sound different but 95% of the time it's not a huge difference. Every once in a while you'll run acroos one that makes a significant difference, especially with the preamp tubes. But in general I don't think they're anywhere near worth the price.
I've always thought of tube rolling as being for bedroom guitarists that sit around obsessing over tiny tone issues but don't really play that much.
Or big time players that can afford to go thru a buncha expensive tubes looking for those few special ones.

Agreed. They've probably become more of a myth passed down from audiophiles I think more than anything. That said, I do run a NOS Blackburn Mullard 12ax7 in V1 of my Marshall. I can hear the difference between that and my Groove Tubes (1993 issue) that was put in many years ago, but only because the GT is a really hot tube. My front end is a little more clear and much less overdriven with the Mullard, but probably only because the GT is so hot. As for tone, it sounds like a Marshall with either tube. When it comes time for new 6550s, they will be something current production.

 

[miroslav]

That said, I do run a NOS Blackburn Mullard 12ax7 in V1 of my Marshall. I can hear the difference between that and my Groove Tubes (1993 issue) that was put in many years ago, but only because the GT is a really hot tube.

You get that a lot...newer production tubes that actually run over spec...like they try to be more than they should.
Is it a good/bad thing...?
I guess it's up to each person to decide. I too kinda prefer a more "mellow" tube up front.

I've got tons of old vintage tubes....though I never paid any of the ridiculously bloated prices you see today for some NOS tubes, but I bought a lot of my tubes like 10 years back...just a bit ahead of the eBay "push" (which I think is responsible for many of the high NOS prices).
I remember buying Baldwin/Sylvania 12AX7 tubes for like $4 each...now they're selling for $20-$30 each...mainly 'cuz they became somewhat of a "craze" thanks to eBay.
They are great for guitar amps...but prices have soared with them.
The main reason I went on a tube buying spree 10 years back was 'cuz there was like a bad period of not much good current stuff, and people were wondering if tube production would just dry up....so I bought a lot of tubes to have for the next 30 years, and I got many at really cheap prices.
Worst case...I can sell them one day on eBay for a nice profit!

AFA as tone differences...well, I don't think it's much of actual "tone" difference. Like...the tone of your amp doesn't change so much, but what I find with some tubes is that the quality of that tone will change...sort of what you experienced with the Mullard-GT comparison.
Often there is a somewhat of a harshness/edginess with current tubes, not all, but most of the cheap Chinese, and I've yet to find a basic Sovtek 12AX7 that is smooth, though their LPS is pretty good.
Also, with current production, the QC from batch to batch and tube to tube is not as good as it was with USA/British made stuff or some of the other European tubes back in the day.
You can find some great current tubes...but also a lot of lemons...and you can also find some lemons with vintage tubes.
I'll spend a couple of hours trying out various tubes from my stock on an amp...and when I hit on a good combination...I don't keep changing them out week after week. In most of my amps it's half vintage/half current production, so I'm not really hung up about using just vintage stuff.

I like the JJ stuff...really love their EL34L tubes, the 12xxx stuff is fairly consistent too, and I've used their 6V6 tubes without issues.
Also the old Russian Svetlana EL34 tubes were great (I have a bunch of them).

Funny...the most I ever paid per tube was for the current production Gold Lion KT66 tubes.
Though they are great tubes.

 

[Seeker of Rock]

Worst case...I can sell them one day on eBay for a nice profit!

Or sell a couple at friend prices to your good buddy Seeker of Rock. I still believe the quality hype, if not totally buying into the tone hype (at least not the night and day differences that are claimed).

I actually have two Blackburns and am going to roll them with the 12ax7s in my Super Reverb soon for shits and giggles, notsomuch in that I want a British tube in the Fender, but just to A/B new and old stock. The Groove Tubes in my Marshall are newish(91/92/93...forget the exact year they were put in), but not current production. I believe they are Chinese.

 

[miroslav]

Maybe you already have...but did you ever try a 5751 tube in the V1 position in place of a 12AX7...?

If you feel the preamp section is a little too "gainy" and overdriven even at lower levels on an amp, and when pushed harder it gets too "hairy" or kinda harsh...try a 5751.

Then turn your channel volume up to where the preamp starts to overdrive again...it's often a "thicker/fuller/smoother" overdrive...and you get a bit more headroom.

I believe the 5751 is like 70% gain compared to a 12AX7.
It sits nicely in-between the 12AX7 and the 12AT7 (which sometimes cleans things up too much).

 

[Seeker of Rock]

Maybe you already have...but did you ever try a 5751 tube in the V1 position in place of a 12AX7...?

If you feel the preamp section is a little too "gainy" and overdriven even at lower levels on an amp, and when pushed harder it gets too "hairy" or kinda harsh...try a 5751.

Then turn your channel volume up to where the preamp starts to overdrive again...it's often a "thicker/fuller/smoother" overdrive...and you get a bit more headroom.

I believe the 5751 is like 70% gain compared to a 12AX7.
It sits nicely in-between the 12AX7 and the 12AT7 (which sometimes cleans things up too much).

Nah, the Marshall with the Mullard is perfect for me. It was the GT that was apparently very hot, and I had actually requested that when I had it retubed by IRC music back then. The Mullard is perfect. I am looking at a blackplate 5751 for V2 of my Super Reverb, though. I use the vib. channel, and the GT 12ax7 in there now is still a little hot for my tastes (when using humbuckers). I've been watching ebay, looking for something cheap but with decent life left. And balanced, since it is the first gain stage position.