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Reliability of Mcintosh pre amps

B

barsur

Active Member
Hello,

as a collector of Hifi stuff (especially Mcintosh and Accuphase), I was always very happy with the reliability of both brands.

Now in the last 12 month I lost three pre amps of Mcintosh with a major default (C22 CE, C 34, C 45). With all the power amps from Mcintosh I had never one minor issue.
So is this only coincidence or are the pre amps from Mcintosh not reliable?

What is your opinion? Which expierence did you have with the reliability of Mcintoshs pre and power amps?

Best regards

Martin
 
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Difficult to answer in english. I know what happend according to the dealer, but he explained it to me in German. My translation in English would be for the C34 and C45 that one of PCB blew up and that the C22 CE had an issue with the transformator. If you want the full text I can scan it and sent it to you. But it is German. Repair of the C34 cost me a lot of money and than it broke again. I didn´t do a repair on the C 45, because I connect now the MCD 301 direct to the MC 252. Dealer took it back and gave me good money. Thanks to the dealer.

Best regards

Martin
 
Since I restore client's C33s on a regular basis I am always interested in possible hidden issues it and the almost identical C34 might have. I think the only reoccurring issue they have are failed op amps causing PS issues and all needing a complete recap. Most C33 are 30 years old and C34s are 25.
 
barsur said:
Difficult to answer in english. I know what happend according to the dealer, but he explained it to me in German. My translation in English would be for the C34 and C45 that one of PCB blew up and that the C22 CE had an issue with the transformator. If you want the full text I can scan it and sent it to you. But it is German. Repair of the C34 cost me a lot of money and than it broke again. I didn´t do a repair on the C 45, because I connect now the MCD 301 direct to the MC 252. Dealer took it back and gave me good money. Thanks to the dealer.

Best regards

Martin
Click to expand...

I have two C34V's. One is perfect, the second has random crackling static especially at turn on but it comes back after 3-4 minutes. I have gotten to the point where I am considering just dumping it regardless of value (I recapped the entire unit) to keep my sanity (my wife's suggestion). Hard to figure out because it is not constant. Maybe a new cap or an old transistor.

John
 
John

If the intermittents don't kill us they make us stronger!

I would swap all the summation op amps (5534s) L for R and see if the problem changes channels.

Also would hard wire with RCA cable the make/break processor loop connections.
 
c_dk said:
Since I restore client's C33s on a regular basis I am always interested in possible hidden issues it and the almost identical C34 might have. I think the only reoccurring issue they have are failed op amps causing PS issues and all needing a complete recap.
Click to expand...

Should we all be scared that an Op-amp with fail and blow up our preamps? That is the only issue? or you think it is so? I've not seen or heard of any cases of that happening on this board. Can you site any such instances?


-Gregory
 
Scared is a little much.....made aware of would be more like it. I have posted in the past, as have others, about updating these op amps with modern replacements.
 
Does it count as a reliability issue if it never works right in the first place?

Referring to the myriad of issues with the digital inputs on the C48/C50...
 
I don't think that counts in this case, since all the preamps that had the problems don't have the digital inputs the C48 and 50 have.

That's a whole other subject. :sigh:
 
With most of the older preamps (like a C28) and tuner-preamps (like MX110z, 113, 117) units, I've not had any problems. With a C32--NOTHING but problems, from the ribbon cables to internal connections and transistors going bad--it was in the shop more than in my house.
 
Hello Gregory,

this is a very good idea with the translator. Here is one copy of the receipt for the C34. I hope the translation makes sense:

Partial fragmentation of the device for measuring time and error analysis. complete cleaning
Chassis and boards. Elimination of cold solder joints, replacement of two
Netzteilelkos, cleaning and conservation of all switches and potentiometers.
Disassembly and repair of the record monitor button.
Exchange of some specific lamps and a series-connected LEDs.
Convert the appliance to 230V mains operation with fuses.
Mounting a foliengeschirmten high-end power cord with high-end plug.
Several days trial run.
Spare parts (cord, plugs, bulbs, LED, capacitors,
Fuses EUR) 132.00
Workload EUR 480.00
______________
EUR 612.00
116.28 EUR plus 19% VAT
______________
EUR 728.28
============

What surprises me, is that nobody talks about my broken C45. This unit was only six years old. The C 34 was more than 20 years old, so I have a little bit more comprehension that it broke.

Also I would like to state, that I am very happy with my C28, C29 and C50.
The C50 is a wonderful amp, it works perfect, also the DAC works perfect, no issue at all. And it has a wonderful clean sound.

Best regards

Martin
 
barsur said:
Here is one copy of the receipt for the C34. I hope the translation makes sense:

* Partial fragmentation [dismantling] of the device for measuring time and error analysis [test and evaluation.]

* Complete cleaning of chassis and boards.

* Elimination of cold solder joints, replacement of two netzteil elkos [power supply capacitors.]

* Cleaning and conservation [preventative maintenance] of all switches and potentiometers.

* Disassembly and repair of the record monitor button.

* Exchange [replace] of some specific lamps and series-connected LEDs.

* Convert the appliance [unit] to 230V mains operation with fuses.

* Mounting [install] a high-end power cord with high-end plug.

* Several days trial run.

* Spare parts (cord, plugs, bulbs, LED, capacitors, Fuses EUR) 132.00

* Workload [labor] EUR 480.00
______________
EUR 612.00
116.28 EUR plus 19% VAT
______________
EUR 728.28
============

What surprises me, is that nobody talks about my broken C45. This unit was only six years old. The C 34 was more than 20 years old, so I have a little bit more comprehension that it broke.

Also I would like to state, that I am very happy with my C28, C29 and C50.
The C50 is a wonderful amp, it works perfect, also the DAC works perfect, no issue at all. And it has a wonderful clean sound.

Best regards

Martin
Click to expand...

Yeah that came through >90% clear.. see markups above. That is a considerable amount to to pay. For 700+ bucks, one could buy a decent oscilloscope and maybe a good digital meter.

The invoice doesn't say anything about replacing signal path or voltage rail caps, or rolling of op-amps. Most of the work above can be done by the enthusiast at their leisure [spare time] and to their own satisfaction. What's missing for the DIY'er [do it yourself] is test gear. Either you invest in some, or take the unit to a Tech.


-Gregory
 
wajobu said:
With most of the older preamps (like a C28) and tuner-preamps (like MX110z, 113, 117) units, I've not had any problems. With a C32--NOTHING but problems, from the ribbon cables to internal connections and transistors going bad--it was in the shop more than in my house.
Click to expand...

I'm thinking of dumping the c32. It is too much work for me and not worth the cost to fix. :thumbsdn:

Still love the c28. :thmbsp:


Steve
 
Hello Gregory,

we are talking here of 700€ what are ca. 1000USD. This was the first repair. It broke six month later again. This time it was a PCB board/Op amp. I didn´t repair this time the unit and gave it back to the dealer, who sold me something else (Accuphase, which never breaks, sorry for this statement) and took the C34 in commision.

Best regards

Martin
 
I have had my C22 preamp since about 1980. Not once has it it failed. I recapped it about 4 months ago.

Not bad for an item made in 1968.

As far as the rest of the McIntosh gear I have, I have had to repair my MR67 that I got with the C22. That was about 6 years ago. A cap in the discriminator can failed. I also had an oscillator tube fail.

My other Mc gear has been pretty good. Had an opamp fail in one of my MC2500 amps. I happened while it was on the bench getting cleaned. I must have blown it up somehow. The PC boards on the MC2500 amps can get leaky so that can be a problem.

The MCD7008 player has been solid save for belts since I bought it 6+ years ago. That really does not count as that is really a Nakamichi player.

The C28 preamp I have has been solid. No failures on that either. I am going to upgrade/modify it for better performance however.

FWIW

Richard
 
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