Pioneer SD-1000 Audio Scope M6526B1B Tube

[kazarkazam]

I have a Pioneer SD-1000 Audio Scope with a dead CRT. It is the M6525B1B CRT according to the manual. I have seen on another post that you can use the CRT from a Leader LBO-310 or 310A in place of the M6525B1B. I have these Leader scopes and one has the 75AKB1 CRT (which happens to also be used in the Pioneer SD-1100 Audio Scope) and the other scope has a C3S49P1 CRT.

It is hard to find any information on these CRT's much less any substitute information. Does anyone know if I can use the 75AKB1 or the C3S49P1 CRT's in place of the M6525B1B?

Thanks in advance for any help or advise. These are nice little units and I would really like to bring it back to life.

 

[Ricktptman]

I just finished a restoration project for both a 1000 and 1100. The 75AKB1 will work. That's the actual manufacturer number of the tube that was in my 1000. It was in the last 10% of its life when I bought it. I believe the M6525B1B number may be Pioneer's proprietary part number. I was lucky in that I found a cache of three NOS. The seller knew what they were so I didn't get them "cheap". But I now have a new one in the 1000 and one spare each for each. I'm still careful about not running them too "hot" in terms of brightness, but I'm no longer afraid to enjoy them. If it took a half Century to kill the first one, I feel pretty good about letting the good times roll. Now, it's a matter of finding time to turn the Silver vintage system (1100) on or my den system (1000) on and listen. My cursory research shows the 1000 to be even more rare than the 1100. All the literature and manufacturing date codes I find (not an easy search) seem to limit the 1000 to 1970-1971 or '72. The 1100 appears to have been sold from '72 until at least 1976, depending on when each model's stock depleted in the retail supply chain. O-scopes are cheap and plentiful. SD-1x00's are neither. Were I you, I'd triage your projects with that in mind. but it's up to the individual. I can buy dual trace (or more) digital scopes all day long on Epay for about a fourth of what one good SD-1x00 sells for. YMMV. But in any event, Good luck!

 

[kazarkazam]

[
Just to be clear, I can use the 75AKB1 in place of the M6525B1B in the Sd-1000?[/QUOTE]

 

[Ricktptman]

Essentially, yes. With points deducted for semantics. Yes, you can use it. In my personal experience, the 75AKB1 is the ACTUAL CRT manufacturer's part number and the M6525B1B is (I believe) a part number assigned by Pioneer TO the 75AKB1. So, in the end, it's a distinction without a difference.
It'll swap out fine. The main thing is that the yoke/pin assignments match the 1000 plug. If it doesn't (in the case of the Leader CRT) I wouldn't try it. But if it does, the worst you'll have to do is realign the 1000 to the new CRT. My 1000 had the 75AKB1 in it, so I think you're home free. But you probably will have to go through the alignment procedure in the SM. I uploaded the service manual to hifiengine recently, so if you don't have it already you can find it there. Good luck.

 

[kazarkazam]

Thanks so much for the help and advise.

 

[jameswicks]

I just finished a restoration project for both a 1000 and 1100.

I have an SD-1000. It is missing the caps for 2 of the knobs. Do you know where I can find replacement caps? Or know where I can buy two replacement knobs?
Photo is attached.
I appreciate your help, and look forward to your feedback.

Kindest regards, Jim Wicks
South Florida, USA

 

[markthefixer]

Ah HAH, YOU bought that SD-1000 on eBay!!!

It's going to be a long stalk on ePrey, and expect to pay exorbitantly for them when they do show up.
Get yourself a paper manual for it, from Stereomanuals.com, the gold standard for available documentation.
It will enhance it's resale value in the future as well. (no affiliation, just a happy customer)

The downloadable version is in hifi engine, as well as other places.

From it I found that A12-631-00 is the part number,
you could start downloading service manuals for other 1971-1972 vintage units to see if any of them could serve as lower cost donors of knobs.

parts.pioneerelectronics.com shows QL-600 (NOT the QL-600A) and sa-500a are worthy of investigation

well........... whaddaya know!!! I am sending you a PM, as to not violate the forum rules!!

 

[Ricktptman]

PM'd. I think you're on the way to being homefree with the out of the box quirks solved now. Mark's idea about knobs is great. Epay's another alternative. Roland is one company that has used similar knobs on some of their amplifiers in recent-ish years. You wouldn't want to swap the whole knob, but you might find a few that you could take the metal cap off and transfer.....I'd try Epay first. I sent you the SM in a .pdf. You're good to go!

 

[markthefixer]

PM'd. I think you're on the way to being homefree with the out of the box quirks solved now. Mark's idea about knobs is great. Epay's another alternative. Roland is one company that has used similar knobs on some of their amplifiers in recent-ish years. You wouldn't want to swap the whole knob, but you might find a few that you could take the metal cap off and transfer.....I'd try Epay first. I sent you the SM in a .pdf. You're good to go!

That " well........... whaddaya know!!! " comment meant that I actually found a maker of reproduction end caps for various manufacturer's knobs, listed under the SA-500a model number, in eBay. In Hamburg, New Jersey. Seller bizcoup. At very reasonable prices no less.

 

[jameswicks]

That " well........... whaddaya know!!! " comment meant that I actually found a maker of reproduction end caps for various manufacturer's knobs, listed under the SA-500a model number, in eBay. In Hamburg, New Jersey. Seller bizcoup. At very reasonable prices no less.

Yes, we’re talking. The knobs with end caps on the SD-1000 are smaller in diameter than the other models mentioned previously in this thread. A digital caliper confirms this. Hoping bizcoup can help.

Kindest regards, Jim

 

[Ricktptman]

Again, without seeming to upscale repetition: Unless the knobs themselves are damaged or otherwise unworthy, the caps are what you're really after. If you have to buy the whole knob, that's a low price to pay, but if they don't match the original, buy just what you need if you can. The total diameter of the knob may be bigger at the base and close to the same size at the crown where the cap goes. But that might also be the case for some small keyboard amp knobs that Roland (I've retired from the gigging business, so I don't see the newer models anymore) used to market. Just like with CRT's, there's more than one way to skin that cat. But resourcefulness isn't optional.