Spectro Acoustics

[boB]

Sorry to hear that fuse blew !  It may mean that the output transistors are bad OR it might just
be a bad fuse.   The schematic for the 202's amplifier module can be found here...

http://k7iq.midnitesolar.com/Spectro-202-scamp-BW.gif

You might take an Ohm meter and compare against the two channels and see if you
can find that the output is shorted or whatever, or, find another 5 amp fuse and
put it in and see if it blows again.  If it doesn't blow, check the output for DC coming out.
Shouldn't be more than around 0.1 volts DC or so with nothing connected.  Make sure
there is no speaker connected when turning it back on though.

If you are uncomfortable doing this, then I can take a look at the module and see if it
is broken or not.

Also, some of the 75 volt filter capacitors would go bad on those amps after a while.
Sometimes it was just the connection on the cap.  You should measure around + and -
68 volts DC with respect to the middle (ground/minus) with good caps.

boB

[JimPat]

CDN-VT: thank you, I may take you up on that offer !!

boB: thanks for the quick reply, I will try my best to follow your instructions. If I can't get it I will get the amp to you when it's convenient for you. I would like to post some pictures here but I'm having troubles, they are too large, i will find a way so everyone can see the 202 amp and the 101B preamp I've acquired. Love them !! I've got pictures of the insides as well, is there a way to get them to you if I can't post them here ?
Thanks again
J

[Westbranch]

if you area using Microsoft picture viewer there is an option ubder VIEW I bekeive to resize the pictures, be sure to do this operation on a COPY of the original and then you will be able to post them...

[onanparts]

Yesterday Robin was kind enough to let me scan some of the Spectro Acoustics history from his archives. Thanks again Robin! 

Pictured here is very early sales literature from near the beginning. I forgot to ask Robin if he remembered what year? 1973, 74, 75?

SDR2 was a partner back then and it states: Manufactured for Spectro by Rob-Ken Audio Products.

From post #5 by Robin in this thread.

When Ken and I started Spectro, one of our first products was the RobKen 2123. The model number came from our ages.

So here it is, most likely the earliest printed literature available on Spectro. 

[onanparts]

Now for the first time ever seen....as far as I know by anyone outside of Spectro Acoustics.

THE ROCK! The 600R Prototype Spectro Amp that unfortunately never saw the light of day until now. 

This was going to be the 500R's big brother. Massive heat sinks! It was very close to being completed when Robin and boB moved onto other projects. Maybe someday boB will have the time to bring this beast to life, but Midnite has his undivided attention with their numerous projects so it may be awhile, if ever. But I will try twisting his arm now and then about it. 

[onanparts]

The rear view. The WARNING is a nice touch. 

[TomW]

The rear view. The WARNING is a nice touch. 

Yeah, much more classy that "No User Serviceable Parts Inside"

[boB]

It was great having you out here yesterday.

I would LOVE to see one of those heatsinks on an MPPT charge controller !

boB

[Robin]

We did have a good day Friday with Onanparts. He got a full days worth of MidNite and Spectro earfuls. We started Spectro in 1973 by the way.
I really would like to see the ROCK play music some day. Bob isn't too far off with his statement of massive heatsinks on a charge controller. We are working on that now.

[onanparts]

Enjoyed looking through the Spectro archives and of course being exposed up close and personal to see products not just "assembled" but actually "designed" and "manufactured" right here in the good old U.S of A. ! 

Speaking of Spectro archives....here are some more goodies.

[onanparts]

A few more more.....

[onanparts]

And a couple more...

[onanparts]

Lab Report on the Spectro P-202 Amp. June 1976.

[onanparts]

Very positive review..

[onanparts]

Just found a 200SR on epay for under a C note shipping incl. and took a chance. Listed as powers up but not tested. As I don't have one in the collection it will be a nice addition.