Need to recap my Classe Audio DR-8 Amps - need suggestions

I had my DR-8 recently serviced by Paul at EBC Electronics in Mansville NJ. I paid $550 including all parts and labor & NJ Tax. Made a huge difference in the overall sound and presentation. Any good electronics technician should be able to that. 

Jon Soderberg of Vintage Amp Repair.   He was a part of Threshold back in the day.   Once in awhile something comes up for sale that has been refurbed by him.   Lot of good reports as to his work.  Ive never had him do anything for me but have communicated a number of times and would definitely go with him considering the wealth of experience he has and is located in Cali.  

Forget about it and use the amps and enjoy them..  If they have an issue, just contact the service centre and send them in (costly, but nice to have that available).

I sent a DR3-VHC in a few years ago (when Classe was owned by B&W) and they repaired it with no problem.

Just had an electrolytic cap crap out on me in my DAC1 D/A converter and just had it serviced locally - nothing 'touchy' like the VHC Darlington output devices that would give a tech any problems. 

Similarly, had a preamp (DR-7, an over  the top assault on the then state of the art preamp, with twin phono stages and a separate power supply the size of your DR8) give some problems, but had a local tech clean the contacts on the twin volume switches - not everything needs to go to the manufacturer.

kdross

Here is a post on re-forming, this guy knows more about electronics in his sleep, than some of the aggro know all's here.
 
" Electrolytics will have a very long shelf life.
But will NEED to be reformed slowly to achieve their specified parameters. I am not surprised that high quality 40 year old electrolytic's still meet specification after reforming."
   
Also from Silicon Chip Magazine on how to do it, if you have the gear and knowledge. (you have to pay for the full article)
 http://www.siliconchip.com.au/Issue/2006/October/Reforming+electrolytic+capacitors?res=nonflash.

As I said I've done many, never been a problem, so long as they didn't leak out any of their electrolyte fluid to start with.

Cheers George

@georgeab Thanks George. Much appreciated.

Dave

Folks; I am new to this site and several of the earlier respondents show more practical experience than I have.  Also, I have never heard of "reforming" capacitors before, however let me state that all electrolytic caps are essentially chemical batteries in construction. Being chemical in nature they get old and "leak" over time. Going through this reforming procedure may indeed offer some improvement in performance, but can in no way make them "like new."  As someone who once had a BSEE degree before going into management, I would highly recommend replacing any caps that are suspect.  On the other hand, if they seem to be working well, let them be. If you send the amp in to a competent technical shop, they should be able to replace the caps and adjust any bias issues for a couple of hundred dollars and that is the way I would go.  Thanks to you regular readers for teaching me something and providing a couple of good names for such restoration, as I have an old Audire amp that I am thing of replacing the caps on.

This information is for Dave (dlcockrun).   The service manual for your DR-9 is located here:   https://www.hifiengine.com/manual_library/classe-audio/dr-9.shtml  The service manual identifies the transistors as MJ15024 and MJ15025.   As stated they were manufactured by Motorola, but now are manufactured by ON Fairchild.   All the other components are marked on the component as you stated.   I would find it highly likely that the preferred sound is not due to difference of transistor manufacturing, but in the transistor bias.   The procedure for adjustment is in the service manual.  Fairly straightforward;   however, be very careful with your probes, get a good clip lead on the emitter when powered down.   Do not use a normal DMM probe that can contact the rail voltage while on the emitter taking out the entire bank of transistors... unfortunately, I am talking from experience (smile).   You could even measure the bias of the preferred sounding amp to see if it matches the recommended bias of 18mV.    If this is not your forte, you likely could find someone locally to perform this function for you.  Just an idea.   One other note, the DR-9 manual (from provided link) is missing a page of the power output transistor section.   The drive section (shown) is what is adjusted is identical to the DR-10 (that service manual schematics are complete) and I find it likely that the power output section is also.  

kdross Don’t listen to Kosst and waste big money on new caps, your amp are hardly used as you say.
Just take it to a good tech to get them re-formed, he knows not to power the amp, he’ll just use a big variac the bridge rectifiers and the supply caps, to re-form them first. Then after he’s re-formed them, he’ll do the same with the pcb board to re-form the smaller on board electro’s.
Parts cost = Zero, instead of at least $800 for all new caps, $1000 for good quality ones like you have now.
Labour cost = much less time hands on in total than replacing them all.

As you can see for just one amp you have 4 large red power supply caps and 5 smaller blue pcb electros. Double this for two amps. Those red ones for memory, I’m sure are Classe branded Nichicons at close to $100 each.
http://www.hifishock.org/galleries/electronics/classe/power-amplifier/dr-8-1-classe.jpg
This is very similar to the Classe DR25 I had to do.
http://img.usaudiomart.com/uploads/large/1304766-classe-audio-dr25-power-amplifier-excellent.jpg

Cheers George

I talked to the Service Dept. at Classe' less than two years ago when they were still a part of B&W about obtaining a part for a TOTL CD player almost ten years newer than the DR-9's. They informed that not only did they not have parts but didn't even maintain parts lists for gear of that era. Their advice was to go through old reviews or look inside the unit and attempt to find part numbers and try to order equivalents from a supply house. So no help at all so I doubt another owner later would be of much help. I happened to find a veteran local tech who could identify the actual transport as a Phillips Pro from his work with commercial units and knew which part to replace. 

I have two DR-9s and wholeheartedly agree with kacomess that these “authentic” Dave Reich-designed amps are special and worth the trouble to restore/prolong their lives.

I bought each from two different sellers. One was box-stock original and one had been “refurbished” by a prior owner a few years back using the Classe-supplied capacitor and power transistor kit. Although the “original” amp still works perfectly well with no signs of electrical issues, the refurbished DR-9 sounds much more open, lively, and detailed, eschewing the long-ago established reputation of the early Dave Reich class A/B amps as sounding dark, rolled off, laid back, etc. (which the original does in comparison to the refurbed one).

I attribute the sonic differences between the two to be more a result of the newer-spec power transistors (and possibly also different bias adjustment) than the replacement of the caps which appear to be identical between the two. Unfortunately, Dave Reich removed the markings on the original power transitions so it is impossible to discern what manufacturer and model they are. However, the newer power transistors that came with the Classe-supplied kit do have markings. They are Motorola. You can see pics of the inside of the refurbed DR-9 on my virtual system page.

kdross, I recommend you try to contact whomever you can muster at the “new Classe” with the hopes that they may still have documentation on the refurb kit component part numbers for your DR-8. It will be worth the effort and expense IMO.

BTW: avoid using the XLR inputs on these amps. The single-ended RCA inputs are vastly superior sonically.

Good luck kdross. I would appreciate it you would let me know if you have any luck with the new parent company as I would love to have my other DR-9 refurbished.

Dave

The DR-9 was the last effort of David Reich at the old Classe. I assume the DR-8 is in the same strata. If so, they are very fine amps and - if in need of aid - I think that they're worth the effort.  As for the "new" company, I've not found them particularly helpful nor responsive.

Classé audio is now owned by the parent company. Sound United. (   soundunited.com. )  they own Denon,Polk,Marantz,Def-Tec,Heos,Boston Acoustics and now Classé.  Maybe contact them and see what they say. I imagine at the least you could find a authorized service center to do the work.  Good luck. I love Classé. I have a CP-800 and 3X  CA-M600’s. Absolutely love them.  

garebear since you know some much why don't you reach out to Classe' and see how far that gets you.  The OP asked about sending them back to Classe' for repair and it is relevant and correct that the company doesn't exist anymore other than as a name brand as part of a holding company.  On another forum two reviewers with long term relationships with Classe' reached out on behalf of someone like the OP and it got them nowhere. But you go ahead and try yourself.  Make sure you have your facts straight before you call me or anyone else out. 

Caps that need reformed are garbage and should be replaced.

This is not correct, I’ve done it many times with new old stock Siemens that have been on the shelf for 15 years or so, and other good quality ones, and I’m sure the ones in the Classe aren’t rubbish probably Nichicons.
So long as it’s done as I stated above it works great, that (10v-20v) is the volts you increase every hour or so.

1: If you have any dc offset coming from the amp, you may hear it at switch on by a good hefty thump through the speakers.

2: And if it has a constant large amount of dc offset you can as gergeab said measure it with a DMM if you have one and know how to use it.
Or after the thump look at the bass driver will be in or out a little more than where it normally sits in it's rest state with no amp on, if there is dc present.

Cheers George

Sorry to hear about your woofers. I would put a voltmeter on the amplifier outputs and see if you have a significant DC offset. That is something that has the potential to take out woofers. If you have DC offset, it could be from something internally faulty or it could just need adjusting. Pretty straightforward procedure, put meter on outputs and tweak pot until it reads 0 +/- 1mV. Here is the procedure from the DR-8 service manual: https://www.hifiengine.com/manual_library/classe-audio/dr-8.shtml
Looks like same procedure as on my DR-10 which I have owned since new. I have no indication that my caps need replacing and I have been using for some 27 years now.

Thank you for the responses.  My amps do not make any noise and are very quiet.  No popping, humming, etc.  My concern is after 1-2 days of connecting my DR-8 Classe Amps and DR-5 pre amp to my Thiel CS2 speakers, the woofers on both speakers went and need to be replaced.  I do not know what caused the woofers to go.  But I did play the speakers at a rather loud volume after installing the amps and wonder if that did my speakers in.  Just do not want to cause more damage to my speakers or amps.  

kdross
I recently purchased two Classe Audio DR-8 amps. The amps were barely used and are in mint condition, but I think I need to have them recapped due to being over 20 years old.

No not really seeing they were barley used this should be tried first, all they would need is to be powered up very slowly 10-20 at a time over a few hours so all the electrolytic caps can "form" themselves again.
This can only be done by a tech using a big variac that can handle the power, other wise the variac will blow.

There is plenty to read on "forming old electrolytic caps" on Google.

Cheers George

You can try United Radio in East Syracuse NY or George Meyer AV in Los Angeles.

FYI: age is not a reason to replace capacitors. When they get worn out the amp will let you know with buzzing and loss of definition in the bass. If they work, leave 'em alone. I'll bet that's what those two will suggest as well.

Classe Audio as it existed as an independent Canadian manufacturer when those amps and preamp were made does not exist anymore.