Old Penncrest stereo console, who made it and should i get it?
 

Hello All! Sat. at the local GW i spy a console stereo out of the corner of my eye. It is branded Penncrest, it is a tube model, with 11 tubes on one chassis, My curiosity is up so i go home and try to find out more info about it with Google. It is a model 662fm-a and the only pic of it is from a SAMS Photofact manual for sale on the -bay. evidently this is the only that has survived or it is a piece of junk no one thought worth the time to snap a pic and upload it to the web.
A few strange things i have noticed about it are, audio output uses 1 7686 pentode in singled ended operation per channel. It uses a straight line magic eye tube for tuning like European and McIntosh Tuners. thirdly this stereo uses a outboard demultiplexer for FM stereo "missing or never installed in this unit". Anyone have one of these or know who made it for JCP? Or if it is worth picking up? The price is $50 today and $25 next Sun.
Thanks all, Logan

I'd get it when it is $25. You can probably add any tube MPX adapter....Using that adapter dates it somewhere in the 1959-63 range, by my reckoning. Single ended can sound VERY good if the engineers bothered to make it good.

Or make your own - I've built two using MC1310P ICs - easy-peasy, just with the datasheet schematic. The chip doesn't require a bunch of odd parts, and will drive a 70ma or less stereo lamp. First went with a Channel Master table radio that had a mux adapter output, and the second went in a Bradford consolette radio/phono I got from a couple at church. It's now in a Pennsylvania dentist's hands.

http://www.datasheetarchive.com/dl/6...ecoder+mc1310p

I tried looking up the output tube number and that number doesn't come up as an output tube. It could be a 5686 or???
It's possibly built by Symphonic or another east coast maker.
It could be similar to the Bradford that used a single ELL80 dual output tube.

Fascinating. I may have to try that (if I can source the chips).

I built a project in school to decode and re-generate MTS stereo from a composite audio input, using my Sony 7" TV-720 to demonstrate.
It was easier to adapt an NTE-743, which is a similar IC to the MC1310, a Motorola chip.

As I fuzzily recall 30 years later, the range of the pilot tone generator on the NTE (an LM-something) could be tuned to 15.7 kHz. But the Motorola IC was designed to be stable at 19 kHz and varying it did not work well.

March 1986 Radio-Electronics has the project for an MTS Stereo decoder using the MC1310 - it's a versatile chip....

You will find in the Jan. & Feb. 1987 RADIO-ELECTRONICS a write-up on a tv stereo decoder with signal processing using an LM1800 & SA570 chips. Was a good design. All the best,Tom.J

Dang it, now I've got 2 more scratch project builds i want to do...You guys are a bad influence. :D

Gee Tom, That's WHEN it was! I had the delusion I came up with that myself. It was the LM1800 tho' :sigh:

This is probably the multiplex that originally came in your (Wells-Gardner) Penncrest:

http://www.searchinforums.com/st/con...-tube-amp/4546

Maybe you can buy it from him.

.

Yep, 7686 there are 3 for sale on the bay. here is a link to a tube data page.
http://www.nj7p.org/Tubes/PDFs/Frank...ngham/7868.pdf

OOPS i meant 7868 time to get new glasses!

I haven't really made up my mind to get this stereo yet. Let me see if this stereo is still for sale on "half price day" I don't have alot of room and money. and it is heavy. It might be better to hold out for a better brand with multiplex already built in.

If the unit is still available, it's worth considering. If it's built by Wells Gardner and has SE 7868's it should be OK. The 7868 is RCA's answer to the Westinghouse 7591, a little better than a 6V6, but not quite a 6L6. Should be around 8WPC.
Some of those private label products were amazing! :thmbsp:

Well i dun gone and did it. I am glad to be able to be the first person to post live pics of a Penncrest 662FM-a stereo console on the web.
I added some pics of the inside.

As I said before, some private label products are amazing. Horn tweeters and large bass speakers, plus a higher end V-M changer.
If it was around this area, I would've bought it, without hesitation. :thmbsp:
Great find!

+1
Looks like a good find.

The firm is still in business, of course, they're not building that kind of equipment. Displays for the gaming industry.
They started in 1925.

That looks like a great console. This is nothing like taking the back off to confirm what a fine set of matched components you got:)

The platter mat on that record changer looks identical to a 1963 Zenith changer I'm working on now. The control levers and tone arm are nothing like it though. Very interesting.

The 7868 was not used often and I only recall working on a Fisher 400 that used them in push-pull.

Thanks Guys! and especially DieselJeep I forgot about these old stereos using good parts in them. The Horn tweeters had a warning sticker on them about disassembling them will void the warranty, and said Jensen Mfg co.
I hooked up a pair of RCA cables to the tape input and connected that to a rca fem to mini audio plug and hooked it all up to a Ipod. Now my niece thinks the stereo if the coolest thing ever!:thmbsp:

Many of the Wells-Gardner built radios from the mid to later 30's were among some of the finest made at the time. Their high tube count radios were more impressive than the Zenith and RCA's of the time.
Chromed chassis and two large speakers, variable IF band-pass.
The largest models used PP 6L6's, the smaller models used 6F6's with a triode connected 6F6 as a driver stage, two stages of IF's etc. :thmbsp:

I just picked up the identical unit for $30. I would have paid that and more for the cabinet alone, but the electronics still work so that was a huge win. The style is great in the MCM den I've been working on, and the unit has a real nice mellow sound to it. I hooked an Amazon Audio Bluetooth receiver to the tape input RCA jacks and can play it from my phone or tablet wirelessly. Neat mix of old and new.

The dials on the set make a lot of noise when I turn them to adjust volume/bass/treble. Sometimes one channel will drop out entirely until I get the dial back into a sweet spot. Any suggestions for cleaning up those connections? I am a total novice when it comes to radios and electronics, so would appreciate any suggestions.

Spray some electrical contact cleaner in to the gap where the terminals are on the potentiometers on the inside of the unit and and turn the pots end to end a few times.

I recommend De-Ox-Id as your contact cleaner. I use it, and find it to be a good balance of high effectiveness and low price. https://www.google.com/search?q=De-O...utf-8&oe=utf-8

The Penncrest name started being used by Penney's in early 1963. Down in my area, there was a tube stereo that had a jPc logo on it. I know it's late '50's or early '60's, but some youngster who isn't even 30 yet said "It's not Penney's, it would say Penncrest on it if it was. They did offer electronics before using the Penncrest line name.

I once had a portable phono that branded Penneys. Below the logo it said "Always First Quality". The same caption that was on all their packaging and newspaper ads.
IIRC, it was one of those one or two tube jobs, with a VM changer. :scratch2:

Thanks! I'm looking forward to working on this. I did confuse this post with another one about a Penncrest, here are other folks' photos of the same model that I got:
Outside: http://i.imgur.com/JRY31Vz.jpg
Under the hood: https://imgur.com/a/ioAOT
Once I get the unit cleaned up I hope it sounds as good as these look!

Most consoles of mid to higher quality (heck even some of the cheapies) usually sound great.

Be aware that this unit is creeping up on 60 being years old. The paper and electrolytic capacitors may still be good. but they go bad with age, use (worse yet extended disuse), and storage conditions...You should consider replacing the capacitors on the amp and tuner chassis. Also the rubber on the changer (motor mounts and idler wheel) can go bad from age too if the motor spins but the platter won't, won't at the right speed or there is regular rumble overtaking the audio there may be bad rubber. The cartridge and styli, as well as tubes may also wear out.

It may be fine now, but vintage electronics just like vintage cars, only survive multiple decades of use through periodic maintenance.

Thanks for the tips! I’m retiring in a couple months and this is going to be a winter project for me. I have a lot to learn but fortunately three generations of engineers in the family who have offered to help. If you looked at the photos, mine has a little darker finish but very few blemishes for a vintage cabinet. I have not had a decent stereo for over 10 years but this makes up for it. Top of the line? No, but a very nice sound and especially for the age.

Cool! It looks like a slightly newer model than mine. Is it a transistor model? mine was tubes but the layout looks like it was done by the same engineering team.

Mr_fixer check post 15 snapshots and you will see that it is indeed tube power. All the best,Tom.J

Well yes i know, but post 15 was pics of my radio not PA_steve's set. I think his is a solid state a few years later than mine.

Ops! My bad (:-). All the best, Tom.J

Ive used the amp out of one like that for sound on my computer. the outputs seemed tired so i replaced the sockets to run modern Russian 7591's in it, since i had those on hand. It really sounds good!

I done that project too.It was great to hear the Tonight Show and Miami Vice in stereo.