Old Marshall Repair

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Drew

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Last week I started a thread about my old modded Marshall sounding off. I took it to a local tech and he just sent me a laundry list of issues. Let me ask you guys if this makes sense and what each of these items should cost:

1. Your amplifier has a Factory Date of 15/9/77, so at 33 years old and a 100 Watts… it is ready for a new power supply. This will include all filter capacitors in the B+ Supply, Bias Supply, Heater Supply and Additional Heater supply circuit.

2.While I have the circuit card unbolted and elevated from the chassis for the Bias Supply and removal / replacement of one of the filter capacitors, I should change out the Diodes. They are a bit fried and the parts and additional labor are minimal.

3. The preamplifier tubes you have installed are a mix of Chinese and Slovakian which are cheap and sound bad. Sorry... I have a nice supply of New Old Stock Military tubes 5751’s which I can install.

4.There are about six audio caps that are ceramic and can be changed out to Silver Mica. I would not change the values, only the composition of the part which will smooth the signal, ceramic can sound brittle compared to Silver Mica. ( Most of the audio signal capacitors are Orange Drops, which are good and do not need replacing as they are made from polypropylene which sounds nice.)

What do the experts say about his list and can somebody tell me what is a fair price for parts and labor?
 
tell him to take a hike on the preamp tubes. that is un-needed and is totally based on user opinion, not required maintenance.

the diode one does not make sense unless the diode is deffective and tests shorted or open. diodes are current driven divices - either they work or they dont. i would not let him charge you much for this.

the only thing you have to be careful with in design as far as diodes do are placement position and voltage rating which either can result in instant damage. otherwise....i see no reason to HAVE to change this part.

the silver mica cap upgrade is also opinionated....but i do agree with him on this one. i do believe it would be beneficial for the amplifier and yourself.

the electrolytic cap job is a must - he is right in saying this.

i would not let him charge you more than $150-175 for the cap job depending on the capacitors he chooses. tell him to use F&T's and not cheap electrolytic capacitors for the price i gave you.

the audio capacitors would be another $20-$50 or so i suppose - depends on the technician. some charge by the part, others charge by the hour.

have him explain what is wrong with the diode(s) to need replacing. if he says upgrading the voltage rating which prevents fire hazards, let him do it. if he tells you anything else, its BS and does not HAVE to be done. i do not have the board here in front of me - so of course his opinion will matter more. but this is my electrical experience with diodes.
 
glpg80":3awinbx1 said:
tell him to take a hike on the preamp tubes. that is un-needed and is totally based on user opinion, not required maintenance.

the diode one does not make sense unless the diode is deffective and tests shorted or open. diodes are current driven divices - either they work or they dont. i would not let him charge you much for this.

the only thing you have to be careful with in design as far as diodes do are placement position and voltage rating which either can result in instant damage. otherwise....i see no reason to HAVE to change this part.

the silver mica cap upgrade is also opinionated....but i do agree with him on this one. i do believe it would be beneficial for the amplifier and yourself.

the electrolytic cap job is a must - he is right in saying this.

i would not let him charge you more than $150-175 for the cap job depending on the capacitors he chooses. tell him to use F&T's and not cheap electrolytic capacitors for the price i gave you.

the audio capacitors would be another $20-$50 or so i suppose - depends on the technician. some charge by the part, others charge by the hour.

have him explain what is wrong with the diode(s) to need replacing. if he says upgrading the voltage rating which prevents fire hazards, let him do it. if he tells you anything else, its BS and does not HAVE to be done. i do not have the board here in front of me - so of course his opinion will matter more. but this is my electrical experience with diodes.
Click to expand...

Thanks for the input. I knew this guy was out of line!

When you say $150 to $175, are you referring to item #1 on my list. He wants to charge me $325 in parts and $200 labor!

For the audio capacitors, he gave me a quote of $25 parts and $75 labor.
 
Drew":2qcspvfb said:
glpg80":2qcspvfb said:
tell him to take a hike on the preamp tubes. that is un-needed and is totally based on user opinion, not required maintenance.

the diode one does not make sense unless the diode is deffective and tests shorted or open. diodes are current driven divices - either they work or they dont. i would not let him charge you much for this.

the only thing you have to be careful with in design as far as diodes do are placement position and voltage rating which either can result in instant damage. otherwise....i see no reason to HAVE to change this part.

the silver mica cap upgrade is also opinionated....but i do agree with him on this one. i do believe it would be beneficial for the amplifier and yourself.

the electrolytic cap job is a must - he is right in saying this.

i would not let him charge you more than $150-175 for the cap job depending on the capacitors he chooses. tell him to use F&T's and not cheap electrolytic capacitors for the price i gave you.

the audio capacitors would be another $20-$50 or so i suppose - depends on the technician. some charge by the part, others charge by the hour.

have him explain what is wrong with the diode(s) to need replacing. if he says upgrading the voltage rating which prevents fire hazards, let him do it. if he tells you anything else, its BS and does not HAVE to be done. i do not have the board here in front of me - so of course his opinion will matter more. but this is my electrical experience with diodes.
Click to expand...

Thanks for the input. I knew this guy was out of line!

When you say $150 to $175, are you referring to item #1 on my list. He wants to charge me $325 in parts and $200 labor!

For the audio capacitors, he gave me a quote of $25 parts and $75 labor.
Click to expand...

the labor i cannot argue. that is his choice, it is also your choice to walk and find someone else if you disagree with it. but i can tell you that the capacitors he wants to replace in the power supply area do not add to $325 for replacements, he gets wholesale purchases on them anyway if he is a legit certified repair center. the amplifier is a JMP style marshall, not a strategy 500 power amplifier. tell him $375 total for everything including parts and labor for only number 1 and to use F&T capacitors - they dont get any better than that IMHO, and that would be fair with the labor he has posted.

that does not mean its cheap though. thats still way out of line to me.

i would charge a flat fee of $120 labor on top of the parts costs (wholesale, not retail) which would be way cheaper than that. if the board requires unsoldering though, then the labor would be more intensive and could possibly rise to his price - depends on the amplifier. but still, that parts price is insane.

75 including parts and labor for the audio caps is fair. those little suckers are more expensive than you think.
 
glpg80":zn9w91os said:
Drew":zn9w91os said:
glpg80":zn9w91os said:
tell him to take a hike on the preamp tubes. that is un-needed and is totally based on user opinion, not required maintenance.

the diode one does not make sense unless the diode is deffective and tests shorted or open. diodes are current driven divices - either they work or they dont. i would not let him charge you much for this.

the only thing you have to be careful with in design as far as diodes do are placement position and voltage rating which either can result in instant damage. otherwise....i see no reason to HAVE to change this part.

the silver mica cap upgrade is also opinionated....but i do agree with him on this one. i do believe it would be beneficial for the amplifier and yourself.

the electrolytic cap job is a must - he is right in saying this.

i would not let him charge you more than $150-175 for the cap job depending on the capacitors he chooses. tell him to use F&T's and not cheap electrolytic capacitors for the price i gave you.

the audio capacitors would be another $20-$50 or so i suppose - depends on the technician. some charge by the part, others charge by the hour.

have him explain what is wrong with the diode(s) to need replacing. if he says upgrading the voltage rating which prevents fire hazards, let him do it. if he tells you anything else, its BS and does not HAVE to be done. i do not have the board here in front of me - so of course his opinion will matter more. but this is my electrical experience with diodes.
Click to expand...

Thanks for the input. I knew this guy was out of line!

When you say $150 to $175, are you referring to item #1 on my list. He wants to charge me $325 in parts and $200 labor!

For the audio capacitors, he gave me a quote of $25 parts and $75 labor.
Click to expand...

the labor i cannot argue. that is his choice, it is also your choice to walk and find someone else if you disagree with it. but i can tell you that the capacitors he wants to replace in the power supply area do not add to $325 for replacements, he gets wholesale purchases on them anyway if he is a legit certified repair center. the amplifier is a JMP style marshall, not a strategy 500 power amplifier. tell him $375 total for everything including parts and labor for only number 1 and to use F&T capacitors - they dont get any better than that IMHO, and that would be fair with the labor he has posted.

i would charge a flat fee of $120 labor on top of the parts costs (wholesale, not retail) which would be way cheaper than that.

50 including parts and labor for the audio caps is fair. those little suckers are more expensive than you think.
Click to expand...

I know the F&T's are about $10-12 each.

So are you suggesting I offer $120 for labor for everything and then wholesale price for all the parts? What's your estimate on what that would be?
 
i would break it down into this:

labor for audio caps - $35, since its his opinion and does not have to be done.

parts wholesale - $25 at most for the audio silver mica's

$150 for labor to take the board out and inspect it, replace the power supply capacitors, and rewire the board. this is assuming a PTP board - not PCB.

$8 per capacitor wholesale charge.

i would do it all for $300 front to back call it even myself - parts included and labor costs for everything.
 
Drew":2mi6b1mc said:
Last week I started a thread about my old modded Marshall sounding off. I took it to a local tech and he just sent me a laundry list of issues. Let me ask you guys if this makes sense and what each of these items should cost:

1. Your amplifier has a Factory Date of 15/9/77, so at 33 years old and a 100 Watts… it is ready for a new power supply. This will include all filter capacitors in the B+ Supply, Bias Supply, Heater Supply and Additional Heater supply circuit.

2.While I have the circuit card unbolted and elevated from the chassis for the Bias Supply and removal / replacement of one of the filter capacitors, I should change out the Diodes. They are a bit fried and the parts and additional labor are minimal.

3. The preamplifier tubes you have installed are a mix of Chinese and Slovakian which are cheap and sound bad. Sorry... I have a nice supply of New Old Stock Military tubes 5751’s which I can install.

4.There are about six audio caps that are ceramic and can be changed out to Silver Mica. I would not change the values, only the composition of the part which will smooth the signal, ceramic can sound brittle compared to Silver Mica. ( Most of the audio signal capacitors are Orange Drops, which are good and do not need replacing as they are made from polypropylene which sounds nice.)

What do the experts say about his list and can somebody tell me what is a fair price for parts and labor?
Click to expand...

Hi Drew,

do you have a gutshot of the amp?
 
Ah Dr Olaf is in :thumbsup:

Please help save this marshall Olaf!!!!! :cry:
 
glpg80":1hi3tzpi said:
i would break it down into this:

labor for audio caps - $35, since its his opinion and does not have to be done.

parts wholesale - $25 at most for the audio silver mica's

$150 for labor to take the board out and inspect it, replace the power supply capacitors, and rewire the board. this is assuming a PTP board - not PCB.

$8 per capacitor wholesale charge.

i would do it all for $300 front to back call it even myself - parts included and labor costs for everything.
Click to expand...
just send it to him...
 
Please stay away from black and dark brown Silver Micas in all positions which are under high voltages (even the treble cap with 180-200V). Those darker ones will die after a while. Not sure if a certain batch was affected by this (they should be able to handle 630V), but we (in a kraut DIYer forum) had dozens (spelling) of cases of faulty Silver Micas over the last 4-5 years.

Go with Muratas instead.
 
Filter caps and bias caps if they are still original, any tubes that test bad, and that's it. Diodes are good or they aren't, they aren't half burnt. That's about $150 plus any tubes in this part of town.
Jerry
 
Thanks for the input guys. He scared me with some of his comments when I was dropping off the amp but I figured I'd let him look at it and see what he came up with.
 
JerryP":1z7a2rv1 said:
Diodes are good or they aren't, they aren't half burnt. .
Jerry
Click to expand...

This is the part of the original quote I didnt understand. If I ever had a tech tell me " The diodes are kinda fried" , Id thank him for his time and find another one. In my opinion , its not worth haggling over prices and what not , because in the end its just going to piss him off. Find a different tech . Its always nice to have a great relationship with your tech and its especially to be able to trust 100% that the work he is doing is necessary and is priced fairly.
 
What Jerry said. I just did my Marshall 100 watter's caps and parts cost me 75 bucks.
 
jerrydyer":1qt2txfd said:
"Kinda fried" = scam
Click to expand...

+1

i mentioned this in my first post. the way the tech worded it seemed like a scam.

his prices are way out of line. hell, if you were a hobbyist and could learn soldering skills and basic electronic safety, you could do your own cap job for $80-120 depending on the brands of caps you use (Jensens are $30 a piece :doh: )
 
Personally if you are in the LA location I would take it to another tech...
Dave Friedman, racksystems ltd.
Would be my first choice. Then Mark Cameron.
 
The first flag for me, and maybe I'm wrong, is when he says "the amp is X years old and it's time to change..." It seems to me that they need to be changed or not based on failure, rather than time. I'm only just learning about vintage amps, just bought a 35 yr old fender and it sounds great on original parts.
 
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