Mesa repairs Scotland area ?

[dmccombe7]

Anyone have suggestions for Mesa repairs in Scotland preferably Central belt area.

Tried Westside Distribution but they dont do Mesa gear now and couldn't offer an alternative in UK.

Not sure if @agedhorse can offer any help ?

 

Dave

[thodrik]

Hi Dave, 

With any amp repair in Scotland I generally use Flynn Amps. https://www.flynnamps.com/

Fortunately/unfortunately I have never had to have my Walkabout repaired in 13 years, but if I did I would probably send it there. They have fixed a fair number of my old Trace Elliot amps and speaker in the past and my brother's old Marshalls. I think that they can fix most types of amps but they really specialise in older valve amps and solid state amps. 

Checking the Mesa website (https://www.mesaboogie.com/support/locations.html?q=United+Kingdom&page=1&t=repair), they have Fretronics Engineering as a recognised repair centre. They operate in the same premises as the CC Music Shop in Otago Street (I am pretty sure that this will be the same premises that Flynn Amps used to operate out of before they moved to their current location). The Fretronics website has a big picture of a Rectifier so I would presume that they would be well placed to assist! https://fretronics.com/. 

Edited November 4, 2021 by thodrik

[dmccombe7]

Sent a message to Fretronics and will speak to the guy who repairs most of my gear over past few years at Glasgow Studio Electronics. His website shows Mesa as one of the companies he has worked on. 

I've also heard of Flynn amps so if all else fails i might try them.

Dave

[thodrik]

Just now, dmccombe7 said:

Sent a message to Fretronics and will speak to the guy who repairs most of my gear over past few years at Glasgow Studio Electronics. His website shows Mesa as one of the companies he has worked on. 

I've also heard of Flynn amps so if all else fails i might try them.

Dave

Let me know how you get on, as it might come in handy for me in the event that one of my bits of of Mesa kit stops working. 

[dmccombe7]

46 minutes ago, thodrik said:

Let me know how you get on, as it might come in handy for me in the event that one of my bits of of Mesa kit stops working. 

Called Glasgow Studio Electronics as he's the guy i've been going to since 2012. He said he's done a lot of Mesa repairs over the years and suggested it probably isnt a tube but he'll run a distortion test thru the full amp and confirm what the fault is.

I'm probably happier using GSE especially as he knows Mesa gear too.

Plus he's always been reasonably priced for anything i've had done.

Dave 

[agedhorse]

Glasgow Studio Electronics is another good option IME.

[dmccombe7]

33 minutes ago, agedhorse said:

Glasgow Studio Electronics is another good option IME.

Cheers @agedhorse i've just replied to your other comment on volume drop out.

Thanks again for replying and appreciate the recommendation.

I'll keep everyone posted on outcome.

Its an older amp so a few minor probs is to be expected. 

I had it running at home at higher volumes for about 2hrs today and it was fine.

Getting checked out next week.

Dave

[Crawford13]

It sounds like you are sorted Dave, but if that falls through, I would 2nd Flynn in Glasgow. They are top notch. 

[dmccombe7]

1 minute ago, Crawford13 said:

It sounds like you are sorted Dave, but if that falls through, I would 2nd Flynn in Glasgow. They are top notch. 

I've looked at them in past and all good reports but i went with GSE and haven't been disappointed. Its good to have back-ups tho LOL

thanks again for replying.

Dave

[beely]

Another you may wish to consider is Dennis Marshall. http://www.dennismarshall.co.uk/

Based near Dunfermline.

[dmccombe7]

9 hours ago, beely said:

Another you may wish to consider is Dennis Marshall. http://www.dennismarshall.co.uk/

Based near Dunfermline.

Bit out of the way for me but always handy to know for future. 

Thanks for this

Dave

[Steve Browning]

Calling @rumblefish. If this i8s a sudden volume drop, he had the same issue. One of the causes was to do with using non Mesa valves. Rob will probably be along to elaborate.

 

Hope it's sorted soon.

[dmccombe7]

2 minutes ago, Steve Browning said:

Calling @rumblefish. If this i8s a sudden volume drop, he had the same issue. One of the causes was to do with using non Mesa valves. Rob will probably be along to elaborate.

 

Hope it's sorted soon.

I looked at valves just in case it was a dodgy connection of the valves or they had loosened off in transit. Both were good tight fits but  i did note that one was a Mesa and the other a Phillips. 

Someone else mentioned this to me and i asked GSE guy if he was aware of it but he said 12ax7 valves are rated up to 400V or there abouts and he cant see any reason why any good quality 12ax7 wont work in that slot. I believe it was the V2 position. 

I'm taking it in on Tues for the guy to check it out. I have spare 12ax7 valves from my Ampeg days before the Mesa that came from Watford Valves. I think they are Harma valves.

Was going to change the valves anyway but a lot of places dont have any in stock at moment and might be one of those 3 mth pre-order things again.

The current valves have been in since i bought the amp and its been fine up until few days ago. It worked fine yesterday at home at same GAIN setting but lower master volume in the house but the valves would be doing the same work at same Gain setting.

Will wait and see what the GSE guy finds.

Would be good to hear what happened with @rumblefish and outcome before i take in for repairs.

[dmccombe7]

I came across the issue on an earlier BC thread about Mesa Mpulse valves Steve.

Seems that you need to use either Mesa or JJ 12ax7 valves if they need replacing.

Dave

[thodrik]

I think that all the stock Mesa preamp tubes in my Walkabout and Big Block have been replaced with JJs (the stock Mesa ones in the Walkabout lasted ten years so they did a good shift!). I didn't know that they 'had' to be either Mesa or JJ's though. I had always thought that most 12AX7 preamp valves were fairly interchangeable. 

When I got my Big Block second hand, all of the preamp valves were of a different brand and had gone a bit microphonic and the amp sounded like a bowl of Rice Krispies when I first turned it on but the amp still worked. 

With my Rectoverb 50 guitar amp, I had some bad luck with new Mesa 6l6 tubes which went microphonic and developed rattles within a short period of time after I bought them. I actually replaced them with Watford Valves' own brand 'Harma' valves (bought as matched for Mesa set) which perform much better for me. The fixed bias of Mesa amps is a great feature, as it makes so tube changing so much easier and quicker.

[dmccombe7]

Is the bias not just for power tubes. Didn't think it was required for preamp tubes. ?

No expert on it.

Dave

[thodrik]

3 minutes ago, dmccombe7 said:

Is the bias not just for power tubes. Didn't think it was required for preamp tubes. ?

No expert on it.

Dave

You don’t need to bias preamp tubes. Just install them and they should just work until they stop working.

[dmccombe7]

5 minutes ago, thodrik said:

You don’t need to bias preamp tubes. Just install them and they should just work until they stop working.

Kinda thought that. Thanks for confirming tho.

[Hellzero]

19 hours ago, Steve Browning said:

One of the causes was to do with using non Mesa valves.

🤣 🤣 🤣 

 

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/

[rumblefish]

My Mesa Boogie MPulse 600 had a problem with V2 where I replaced the valve with a Tung Sol valve only for it to fail twice.

The outcome was that using only Mesa Boogie spec valves will operate correctly in the V2 cathode follower position.

Trust you get you amp sorted OK.

Regards Rumblefish 

[dmccombe7]

5 minutes ago, rumblefish said:

My Mesa Boogie MPulse 600 had a problem with V2 where I replaced the valve with a Tung Sol valve only for it to fail twice.

The outcome was that using only Mesa Boogie spec valves will operate correctly in the V2 cathode follower position.

Trust you get you amp sorted OK.

Regards Rumblefish 

Looking from the front of the amp what valve is V2 as i cant see any markings on the board.

I found your thread from 2017 i think it was and i've let the repair guy read it so he knows what's been happening with some valves.

Thanks for getting back to me.

Dave

[Hellzero]

Next time, don't forget to put Fender strings on your Fender bass, use a Fender pick, plug it to your Fender amp using a Fender lead and wearing a Fender T-Shirt, otherwise it won't work. 🤪

 

Come one, this is utter nonsense !

 

Show this to any amp maker or repairer and he will laugh for hours : Beware Mesa Boogie amps only work with Mesa Boogie valves !

[dmccombe7]

4 minutes ago, Hellzero said:

Next time, don't forget to put Fender strings on your Fender bass, use a Fender pick, plug it to your Fender amp using a Fender lead and wearing a Fender T-Shirt, otherwise it won't work. 🤪

 

Come one, this is utter nonsense !

 

Show this to any amp maker or repairer and he will laugh for hours : Beware Mesa Boogie amps only work with Mesa Boogie valves !

I have seen a few on line reports of it while researching the problem i experienced. Perhaps its just a valve quality or spec issue.

The guy i use said ecc83 valves are rated up to circa 400V and from what i've read the Mpulse 600 runs at 390V. For me that's quite close to spec limit and maybe the poor quality valves are failing after a while. ?

I have no idea as i'm not an expert in this area by any means so i can only take advice from others with similar amp problems. 

One of the posts i read was from an electronics engineer who repaired his own amps and he came across this same issue and changed an item on the board to drop the HT voltage to the valve in line with other valve amps. 

Dave 

[atsampson]

25 minutes ago, dmccombe7 said:

The guy i use said ecc83 valves are rated up to circa 400V and from what i've read the Mpulse 600 runs at 390V.

 

I'm not sure whether this is the case in Biggar, but there are parts of Scotland where the mains voltage is right at the top of the permissable range - here in Dundee my mains supply is typically 247V (the maximum is 253V, i.e. 230V + 10%), and I've seen 248V reported near Edinburgh. So any equipment using an unregulated power supply can end up with supply voltages rather higher than the typical values it was designed for...

[dmccombe7]

16 hours ago, atsampson said:

 

I'm not sure whether this is the case in Biggar, but there are parts of Scotland where the mains voltage is right at the top of the permissable range - here in Dundee my mains supply is typically 247V (the maximum is 253V, i.e. 230V + 10%), and I've seen 248V reported near Edinburgh. So any equipment using an unregulated power supply can end up with supply voltages rather higher than the typical values it was designed for...

A lot depends on where you are on the supply feed. I live in a village and i'm one of the first houses after the transformer and at one time all my home light bulbs were going one after the other. I have an electrical background so tested myself and the voltage was 250V Contacted Scottish Power and they put a monitor on the house and found it spiking very regularly to 262V They dropped the tap on the transformer which is located in the field behindme on a pole. Been ok since but the engineer said the voltage at the far end of the street was approx 10V lower than mine so its a bit of a balance act to get it right.

The problem happened at a rehearsal in Wanlockhead but the Mesa has a rather large transformer and pretty sure it could cope with voltage changes. Nothing else was affected just my amp.

On the gig last night the amp worked fine altho i turned the amp off when not in use plus i decided to drop the Gain a bit and reduce the drive on the tubes. No idea if these things stopped the volume drop but the amp wasn't on any more than approx 1hr 30 mins at a time.

Dave