HELP! - Need a Repair Recommendation for my Raysonic Amp

After 5 years of flawless service, my Raysonic SP-66 tube integrated wouldn’t power up yesterday evening. The fuse at the electrical input was blown, but it still didn’t power up even after I replaced the fuse with one that tests good. I took the bottom plate off, looked around inside, and didn’t see anything obviously wrong. The 2 internal fuses tested good.

It ocurred to me that the power button was probably in the ON position when I went to start listening. This suggests that either I accidentally left it on the last time I listened, or one of my grand-children turned it on, and it over-heated. I also noticed a paint blister on one of the transformer covers suggesting that it over-heated.

My suspicion is the power transformer, but I don’t how to confirm it, or replace it if it is in fact the problem.

Raysonic is long gone and they had a reputation for being secretive with product details, so I doubt that anyone will have schematics or parts values.

The amp has been a pleasure and it is a perfect match for my CD128 CD player which has also performed flawlessly.

Therefore, I would very much like to get the amp repaired, as long as it isn’t cost-prohibitive, but I don’t know who to turn to, much less trust, to do the work.

I would hope that a well-qualified tube amp technician would be able to fix this even if they are not specifically familiar with Raysonic. I just don’t know who that is.

So, I would appreciate suggestions/recommendations of someone who may be able to help me out.

Thanks in advance.


Shouldn't overheat merely being left on. If it did, the transformers would be the last to get hot. Transformers don't generate hardly any heat in normal operation. They tend to last pretty much forever. But they are made of coiled wire, which if poorly insulated could short and that would create a whole lot of heat. You could test for that pretty easy with a volt/ohm meter and some basic transformer knowledge. Or like you say any reasonably good tech should be able to diagnose and fix. I would call your local audio stores and ask for a recommendation. 
The old US Distributor might be able to fix it (sorry forgot who, but I think he's in PA; I searched 4 pages but did not see him). He was no help for my Raysonic 228, which sits in a box to this day, some 6 years later
Unless you are 100% sold on tubes Underwood HiFi has a fab sale on a couple W4S integratedes
It seems unlikely that the power transformer has failed- a rectifier is far more likely. .

Power transformers have to be dipped in something very much like varnish to help them have low mechanical noise. Then they are baked- so you can get bubbles. This is not to say that the transformer hasn't failed; to test it all the secondary circuits have to be opened so that there is no load on the transformer whatsoever. If it continues to blow fuses then you know its bad.

The blister on the transformer cover, is something to be concerned about. The "why" more than anything..That's hot!!

Pulling the top on the transformer and doing a "look see", if you can. If it's burnt, it's burnt.. The ol sniff test goes a long way, too, does it smell burnt?
Did you pull the valves and see if it will stop blowing fuses.  If it turns on, look to the valves. Is there a chance one blew and that caused a fuse to blow.  Happened to me more than once.
I've lost valves that caused a resistor or two to fail, and the other way around, lost resistors that blew a valves..

If it won't power up, MAKE SURE the fuse is good, (could have blown) pull all the valves and check again, if not, look for a second fuse inside. Then make sure the on/off button didn't go bad.

One visual, the transformer. The on/off, a DMM. Unless you lost a valve it's shop time.. You don't need a schematic, but it can sure help in some cases. Probably no schematics because it was scribbled on a paper bag.. Their not that complicated of a circuit.. No matter who made the amp..The reason there is no information is because there never was, very common in the valve preamp/amp world..


Thanks for all of your input so far.

I agree that simply leaving the amp on shouldn't cause damage.

As I said, I know just enough to be dangerous.  

I live in Lafayette, LA and the closest thing we have to an audio shop these days is Magnolia inside Best Buy.

What would a rectifier look like?

I haven't tested the tubes yet.

I put a fresh fuse in and it doesn't blow when I push the power button on.  Nothing at all happens.  Pulled fuse and checked again.  Still good.

Shipping this thing back and forth is going to cost a small fortune, so I am trying to avoid that.  

Any suggestions for a tech in Houston or New Orleans?  I will traveling to both of those cities once restrictions are lifted and I could hand-carry to avoid shipping cost and risk.

Thanks again.
I put a fresh fuse in and it doesn't blow when I push the power button on. Nothing at all happens. Pulled fuse and checked again. Still good.
Was it plugged in properly (did it light up)? If it lit up but nothing happened, in my estimation the power transformer is off the hook.

If you don't know what the rectifier looks like, then its also a good idea to *not* go looking for it!

I have experienced your problem with several other amp's and each time, as suggested by oldhvymec, I lost a resistor in the bias circuit, replaced it and all was fine. FWIW there are quite a few manufacturers that use a 'sacrificial' resistor as opposed to a fuse. PITA IMHO, especially for some one who can't do his own repair work. 
Was it plugged in properly (did it light up)? If it lit up but nothing happened, in my estimation the power transformer is off the hook.
Did what light up?  The lights on the face of the amp did not come on.  The fuse is in the fuse holder inside the IEC connector.
quite a few manufacturers that use a 'sacrificial' resistor as opposed to a fuse.
Well, that sucks.  Should I be able to see obvious signs of failure?  The are quite a few resistors in there.
So, I reached out to Parts Connexion, and Chris Johnson responded that he is confident that they can help me out. :~)
Not crazy about shipping back and forth to Canada, but he is going to let me use their shipping discount.
He has a very positive outlook, unlike several of the other people I contacted.
I will update this post as things progress.
Thanks for all of your support.
I believe the person in Pa that was referenced  was Steve at Quest for Sound.   I bought a Raysonic SP 100 Integrated from him and about 1 year later it was hit by a lightning surge and knocked out the control panel.   He couldn’t fix due to lack of parts but said it was useable as a power amp.
i then bought a Raysonic SP-200 integrated that I enjoy to this day.  I understand the love for the brand’s sound.
Best Wishes
And the answer is Stephen Monte at Quest for Sound!

Quest for sound has a CD168 posted for sale, so I sent them a message asking if they could possibly help.  Stephen quickly responded that they would be glad to take a look and trouble-shoot for a $65 fee (applied to repairs if made).  

I shipped it on Monday using their FedEx discount and it got there Thursday.  Anxious to see what they find.

I will update as things progress.

Thanks for your input and support.
Stephen Monte at Quest for Sound informed me last night that the center power transformer is toast.  He is not aware of any source for replacement parts, and getting a custom job done would take lots of time and money.  :~(

I don't want to stick it in the closet and I don't want to trash it.  Do you think this is something that somebody might want to salvage parts out of, or make a project out of?

I guess there is always the long shot that somebody out there has another one with different broken parts that could combine two broken ones into one good one.  

Any suggestions would be appreciated.  Thanks.