Mesa repairs Scotland area ?

[agedhorse]

On 06/11/2021 at 04:23, Hellzero said:

🤣 🤣 🤣 

 

Mesa Boogie valves are rebadgeg Chinese or Russian valves...

 

Valves are valves and as long as they are quality ones, they are the almost the same with minor sounding differences, but sometimes microphonic (a 12AX7 is a 12AX7 and they all are interchangeable).

 

The only big difference is the way and where they are made.

 

The military grade 7025 for instance is a ultra high quality long tested with very low tolerances and measurements 12AX7.

 

Do a simple trick if you don't believe me : take some acetone and remove the rebadgeg Mesa Boogie logo and you'll see the acid engraved original Sovtek logo or Electro Harmonix or another brand, or simply a superb Made in China !

 

At some time, there were only 3 places left in the world making valves : Russia, China and old communist block.

 

The rest is pure bullsh*t marketing.

 

The totally fixed power valves bias à la Mesa Boogie is not a good idea at all, but again a marketing trick as power valves must be biased when changed (or getting old) to become perfectly matched, especially if you're using a push-pull designed amp, but a fixed bias is, in fact, a variable bias that becomes fixed when the bias is correctly adjusted.

 

It bears the name fixed bias by opposition to the automatic cathode bias.

 

The preamp valves are cathode biased, but could also be "fixed" biased for a "perfect" sound if you wanted too, but (again) you would need to change the bias system to a fixed bias one which would be useless as the cathode bias in itself is perfect.

 

Check this : https://www.ampvalves.co.uk/cathode-bias/

If you knew how many tubes marked 7025's are in fact just plain 12AX7 in "different clothes" (counterfit), you might be surprised.

 

If you knew how many tubes we reject because they are either out of spec, noisy or microphonic, you might be surprised.

 

If you knew where these rejected tube end up, you might be surprised.

 

If you knew how many issues related to a user or tech not understanding the concept of correctly biasing an amp, you might be surprised.

 

Preset bias and "matching tubes for that bias level" is an essentially foolproof way of being able to change out power tubes without the need to re-bias, as well as keeping fingers out of the electronics. This way the bias is exactly as the designer intended.

 

Your comment about "bullsh*t marketing" is uncalled for because it's based on your lack of knowledge of why these decisions were made. You don't have to agree with them, you don't have to buy our amps either, but calling it bullsh*t isn't right.

Edited November 8, 2021 by agedhorse

[Hellzero]

7 hours ago, agedhorse said:

If you knew how many tubes marked 7025's are in fact just plain 12AX7 in "different clothes" (counterfit), you might be surprised. I know.

 

If you knew how many tubes we reject because they are either out of spec, noisy or microphonic, you might be surprised. I know.

 

If you knew where these rejected tube end up, you might be surprised. I know.

 

If you knew how many issues related to a user or tech not understanding the concept of correctly biasing an amp, you might be surprised. I know.

 

Preset bias and "matching tubes for that bias level" is an essentially foolproof way of being able to change out power tubes without the need to re-bias, as well as keeping fingers out of the electronics. This way the bias is exactly as the designer intended. I know.

 

Your comment about "bullsh*t marketing" is uncalled for because it's based on your lack of knowledge of why these decisions were made. You don't have to agree with them, you don't have to buy our amps either, but calling it bullsh*t isn't right. I know.

 

The preset bias and grading valves idea is a way to get people to buy your valves if they want to be sure that their amp will run the proper way, when it's so fast and easy to correctly bias an amp when you know how to do it.

 

I also know that you've done this to avoid people (bad techs included) to put their hands inside a valve amp and die because of an electric schock, which was, hélas, quite common during the all valves items era.

 

Thanks for confirming your valves rebadging and selection system, which is a clever idea (the late Aspen Pittman was a visionary) as you do the good tech job, but being more transparent about it would be a great step forward.

 

That said, I still love the Mesa Boogie 400 and 400+ heads which are still terrific today, just like the Studio (and DC too, of course), the Rectifier and, of course, the Mark series.

[dmccombe7]

So its more about high quality valves for use in Mesa amps. You want the best valves for the best amps. 

Dave

[Steve Browning]

... and (wait for it) Mesa don't actually have their own valve factory. I feel cheated! 🙂

[dmccombe7]

8 minutes ago, Steve Browning said:

... and (wait for it) Mesa don't actually have their own valve factory. I feel cheated! 🙂

That could be a deal breaker for me. Do i now cancel my TT800 or take the chance that the valves will be ok......... 

This all confirms to me that Mesa put a lot of effort into getting the highest quality parts for use in their amps. That can't be a bad thing.

Dave

[thodrik]

If you are not a qualified tech or do not have the correct equipment to bias an amp then biasing an amp is an alien concept and not something that a lot of players want to 'dabble' with. Having an amp with a pre-set bias is a real benefit to me personally. If a power tube goes in my Mesa Rectoverb, I just need to buy a new set of tubes (either Mesa branded or ones which I am confident have been measured to be an equivalent to a Mesa set). Job done. Very handy if you are on tour or at a gig. 

 

If a power tube goes in my Trace Elliot V6, I'm probably going to send it to a tech that I trust, which in my case is about a 6 hour drive. I could try and fixing it myself but I could end up killing myself or doing something worse like damaging the amp. 

[dmccombe7]

4 hours ago, thodrik said:

If you are not a qualified tech or do not have the correct equipment to bias an amp then biasing an amp is an alien concept and not something that a lot of players want to 'dabble' with. Having an amp with a pre-set bias is a real benefit to me personally. If a power tube goes in my Mesa Rectoverb, I just need to buy a new set of tubes (either Mesa branded or ones which I am confident have been measured to be an equivalent to a Mesa set). Job done. Very handy if you are on tour or at a gig. 

 

If a power tube goes in my Trace Elliot V6, I'm probably going to send it to a tech that I trust, which in my case is about a 6 hour drive. I could try and fixing it myself but I could end up killing myself or doing something worse like damaging the amp. 

When i started work as an Instrument Tech in 76 most of the instruments were valves so i started off with old valve amplification and aware of the hazards involved but that all changed within a couple of yrs and by 1980 it was all electronics as we recognise these days. We did have a large stock of spare valves in our stores that i used to "borrow" as i had store keys at weekends LOL

I wouldn't tackle a power amp valve either. Like you i'm ok changing a preamp valve.

I have 3 off Harma STR ECC83's i bought as spares for my SVT4 and from what i've read they are ok.

Problem is i dont actually know where the fault lies in my amp.

Dave

 

Edited November 8, 2021 by dmccombe7

[dmccombe7]

Something i have realised is that using with the punk band i run passive basses and input switch set to passive. In Glam band i use a Sandberg VM4 in active mode on amp. 

The active mode drops the gain and the tone changes quite a bit with the aggressive edge disappearing.

Makes a huge difference with Jazz or Precision basses in passive mode. Little overdrive cuts thru really nicely.

If i use the P bass in active mode it becomes very tame and more mellow sounding.

I've only been with the punk band for approx 4-5 weeks and only done a few rehearsals with the amp and 1 full  2.5hr gig. Before that it was always in active mode for my VM4. I'ts possible the valves weren't being driven as hard till i started with punk band.

Dave