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Amp repair cost — is this right?

I recently sent my Musical Fidelity a308cr power amp off to be recapped. This amp is somewhere around 16-18 years old and one of the power caps failed. I contacted Musical Fidelity and sent it to a repair shop they recommended. Today I received an estimate to replace 18 caps, 8 of which are large power caps, resolder the boards, and re-bias the transistors. Basically a full overhaul. The quote I received, including return shipping (prob around $100) Is over $1,300 which possibly exceeds the value of the amp. That doesn’t include the $115 it cost me to ship it out. Having never had an overhaul done on a power amp like this, I’m wondering if anyone with experience can tell me if this sounds right. I guess I was expecting something more like $600-$800 but I don’t know why since I really don’t have a frame of reference. Perhaps it was the assumption it might be 4 hours labor (say $400) plus max $200 for caps. Is $1,300+ on track? Either way I’m going to be out the shipping cost plus a $160 fee paid for the estimate.
jnehma1
drbarney1's avatar
drbarney1
180 posts
 
The cost of repair is why I build my own amplifiers. I have the good fortune of liking SET amplifiers, which are very simple to design. They are easy to repair if anything goes wrong. I notice your describing a problem with power supply capacitors, which too often go bad after a few years. This problem is with high Voltage electrolytic capacitors which have a limited shelf life. Building my own I am free to use polypropylene power supply capacitors instead which have an unlimited shelf life and do not wear out. For the 1kV power supply to my final stage of SET amplification I use polypropylene capacitors rated at 2400 Volts. It costs little to use overrated components which will not go bad in the future.
I build my own electronics where I can. One exception is I do not have the manual dexterity it would take to hand wind coils in a moving coil phonograph cartridge.
itsjustme
682 posts
 
In Australia a "reputable repair shop" charges $115-$130aud per hr that $80-$90usd.
Like I said it would take a tech that "cares" about a day to do this properly heat soaked and biased back up. And then there’s the "quality" parts 16 x large power supply caps
https://www.newark.com/cornell-dubilier/381ll682m063a052/cap-6800uf-63v-alu-elec-snap-in/dp/54AH2158...
and around 20 smaller electrolytic caps.
THE PRICE SEEMS FAIR!!!!!!!!!!!!!!!!!
Cheers George



Now George, there you go bringing data in... can't have that.:-)
Surprised how costly those caps are.  I buy them quite a bit "better" but yea, they cost!  And to the above folks talking about "better" caps - by virtue of being new the large 'lytics will work much better.  But we are  talking about electrolytic capacitors. These are not audiophile pretty much by definition - they will be paralleled with much better film type caps (i hope!).  So will it be better?  Than B4, yes.  better than new?  Likely not much, although we can buy larger caps in the same package today, so maybe in that respect. Will it last 20 years?  The ones i did already were 30 years old.
CDE are very good caps.
G


itsjustme
682 posts
 
Building my own I am free to use polypropylene power supply capacitors instead which have an unlimited shelf life and do not wear out. For the 1kV power supply to my final stage of SET amplification I use polypropylene capacitors rated at 2400 Volts. It costs little to use overrated components which will not go bad in the future.

Uh, so how much does it cost you and what's the size, using polypropylene film caps, for a modest power supply (remember the OP's amp is solid state) of maybe 2400uF at 600V (for your tube unit). Now think, 50,000uF at 63V (total) for his solid state amp.
I believe some ROM data points will show the impacticaility of this path especially in an existing form factor.
Just some quick estimates - among the most affordable PP caps are Wima.  A 1uF/100V cap is roughly a buck.  Maybe $0.50 in large quantity. (e.g.MKP-10 series).  x 50,000. Math seems simple to me!
Oh they would also be the size of a carry-on suitcase.
G





audio2design
1,351 posts
 
This is 3-4 hours tops for someone experienced with the equipment and product knowledge. For someone who is not it could be 8 hours though with the right equipment I have no idea how I would spend 8 hours replacing 18 caps. Setting bias takes minutes and you work on something else while it is warming up.  Desoldering a cap, cleaning the holes, and resoldering should be a few minutes per cap. Assembly and disassembly time and overhead for parts ordering packing and unpacking must be considered.

Equivalent or given today's parts better components as pointed out is a few hundred dollars at best.

There is overhead for parts and also overhead costs in case they break it. $800 is reasonable, $1300 isn't. That sounds like a premium price for someone to "figure it out".
tkhill's avatar
tkhill
89 posts
 
Get a second opinion. I've been very happy with HiFi Heaven in Falls Church, VA.

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