Music Man 410 trem prob.

[Sea Chief]

Sea Chief , there should be an internal trim pot for the tremolo mounted on the circuit board, as mentioned by Leo_Gnardo above (you would be well advised to remove him from your ignore list so as not to miss out on pro tips).

According to the service bulletin the trim pot is "second to the left (looking from the front)". Mark it's setting before you touch it so you can set it back to the way it was if need be. Try tweaking it a little bit either way and see if it makes any difference.
If any doubt about which trimmer, post a picture of the circuit board.

I wonder what " 2nd to the left" means though?! Looking from the front. I mean theres either the left one, or right one.

Maybe its a language thing.. but doesn't compute into uk english too well. Thx SC

[Sea Chief]

SC: "sounds gorgeous.. but for the tremolo. Its doing a sort of double-pulse, instead of a strong single pulse. Da-da... Da-da... Da-da... etc ( a strong usual pulse followed immediately by a lesser sort of ghost pulse"

IIRC there's a trim pot (pre set for Brits) to adjust the balance of the trem LFO signal. Important to identify the correct pot so as not to inadvertently change bias instead. They're both blue discs maybe 15 mm diameter.

Somebody let SC know. I'm on his ignore list. Small wonder because as we all know he likes to ignore good advice. And I got tired of delivering it to him. But I'll make a brief exception just for today because I'm in an inexplicable good mood. Don't worry that will fade soon I'm sure. Good luck campers!

Youre defo not anymore, many thanks for the info LeeG. Yes I assumed t'other one was bias.. so very important i dont faff with this one.

Ive put up a inside pic of amp. Thanks SC

[Leo_Gnardo]

Are these main caps here showing signs of 'leaking' ? Ie some beige gubbins has popped through the top, same on other one. Thanks SC

Yes, replace without hesitation. Age alone suggests the old ones should be replaced. Breaks in the seals, seals the deal. F&T offer an exact value replacement. I'm sure they're available in UK. Made in Germany. FWIW in the USA, $9.00 each at Antique. Hopefully you will find them at an equivalent price. F&T have an excellent reputation.

[Sea Chief]

Yes, replace without hesitation. Age alone suggests the old ones should be replaced. Breaks in the seals, seals the deal. F&T offer an exact value replacement. I'm sure they're available in UK. Made in Germany. FWIW in the USA, $9.00 each at Antique. Hopefully you will find them at an equivalent price. F&T have an excellent reputation.

Hi LG, been perusing f& t caps myself.. but not so easy to get, & 4x price over here. Mfr in de.. & $9 for you?! You lucky things yous lot.

[Sea Chief]

Leo_Gnardo could you confirm for me, in my amp photo 3 posts back, that the tremolo trimpot is the LEFT one in the photo? And the RIGHT one, is bias?

That would e helpful, thanks if so. SC

( edit: just found/ ordered 2 x f&t 100/450 from a gtr tube amp place in uk).

[Leo_Gnardo]

Leo_Gnardo could you confirm for me, in my amp photo 3 posts back, that the tremolo trimpot is the LEFT one in the photo? And the RIGHT one, is bias?

That would e helpful, thanks if so. SC

( edit: just found/ ordered 2 x f&t 100/450 from a gtr tube amp place in uk).

Offhand I do not know. If you have a voltmeter, you can put negative (black) lead on chassis and with red lead, probe the metal tabs on the trimpots. One will show negative DC voltages appropriate to bias, say around -24 to -30V for this amp. That would be the bias pot. The other one must be the tremolo balance. Can't do any harm by dialing the trem balance back and forth. Hopefully you will find a setting that gives you a normal sounding trem.

I wonder what " 2nd to the left" means though?! Looking from the front. I mean theres either the left one, or right one.

Maybe its a language thing.. but doesn't compute into uk english too well.

I find it ambiguous too. Measure with voltmeter then you'll know.

If I had a truly photographic memory, or a Musicman amp in shop for service I would be able to provide a better answer.

[g1]

I wonder what " 2nd to the left" means though?! Looking from the front. I mean theres either the left one, or right one.

Maybe its a language thing.. but doesn't compute into uk english too well. Thx SC

It is a little vague. 2nd to the left, starting from the right.
In your pic, trem trimmer is the left one, bias trimmer is the one on the right.

[Sea Chief]

It is a little vague. 2nd to the left, starting from the right.
In your pic, trem trimmer is the left one, bias trimmer is the one on the right.

Hi g1.. well yes i did think "2nd to the left left" meant the one to the left, if you start from the right.. even tho it doesn't specify from which side you count from! Total daftness.

Anyway good, as I suspected. So is it just a question of tweaking this ' to where i hear it sounds best' -?

Thanks, SC

[Sea Chief]

Fantastic.. all sorted, the easiest & fastest amp fix ive ever had! Just 3 mm of adjustment.

Many thanks chaps.. what Id do without this fine site, Ireally don't know! Prolly shocked myself with 700v by now!

Im doing a recap of the two big 100/450 any day, so I might need to do a new ' general service mm 410-65 ' thread (& draing those caps.. jeez has to be serious priority too!).

Gratias amigos, SC

[pdf64]

Hi LG, been perusing f& t caps myself.. but not so easy to get, & 4x price over here. Mfr in de.. & $9 for you?! You lucky things yous lot.

https://modulusamplification.com/FT-High-Voltage-Axial-Capacitors-High-Quality-P5303508.aspx

https://www.hificollective.co.uk/con...ytic-capacitor

http://www.askjanfirst.com/eindex.htm

[Sea Chief]

https://modulusamplification.com/FT-High-Voltage-Axial-Capacitors-High-Quality-P5303508.aspx

https://www.hificollective.co.uk/con...ytic-capacitor

http://www.askjanfirst.com/eindex.htm

Hi there pdf. Yes thanks. I did in fact just beforehand find some from hotrox.. is this the right 'type' ( A or B i dont understand)..

https://www.hotroxuk.com/f-t-axial-lead-capacitors.html

My trem is lovely & prominent now, just as i recall sounded so good on these amps. Doesnt like it when i dial in the preamp ' volume ' to 10, getting some very nice distortion: the trem effect is pretty much nullified then. But can try ironing this out when i recap it i a few days.

Oh boy, after 30 years toiling with sooooo many, I have at last.. found my amp (& only £450 too!!).

Thanks SC