Seeburg USC1 with TSA10 Amp Treble but no bass

Hi Lenard,
Pull the speakers--check them with a meter( approx. 4 ohms--5 ohm system)--if good, it's the wiring, somewhere between "that" plug, and the connectors on the speakers--if the speakers are open--speakers are bad-- See the Service Manual for wire routing ( don't recall, but they did use a LOT of wire/plugs in that model, for some reason ??) Ron Rich

Ron, I pulled both speakers tested both and both have no reading OL. I guess I will order 2 woofers from ebay. Thiers a seller on that has several 12" 5 ohm Utah woofers that fit this juke for a fair price in California.. Thanks again to you and Rob for helping me through this. You don't know how much I appreciate all your guys help. Learning this is fun but frustrating, but I see many more jukes in my future. I love to see these old 45 record players playing music..
After I get the woofers I will let you all know the outcome.

Thanks, Lenard

Lenard,
You are welcome--if that "seller" is Bill Butterfield (MFFE), please say "Hi" from me !
Ron Rich

Ron Rich wrote:Lenard,
You are welcome--if that "seller" is Bill Butterfield (MFFE), please say "Hi" from me !
Ron Rich

Yes that is who I bought the speakers from, I will say hi to him for you and I will mail you a money order for that book of yours on Monday. I need that book in my life seeing I am buy a couple more Seeburgs next week.

Lenard, I'm puzzled as to why the external speaker you tried didn't have any bass either.

Ron will probably disagree here but, Seeburgs generally don't blow their bass speakers. the gain structure in the amp and tone shaping are such that the machines never get loud enough to clip or blow the woofers. That is IF the amp's AGC is working properly. The amps are designed with an excess of gain and the AGC attenuates it depending on how 'loud" the record is. If the AGC fails (mostly due to the feed-through connectors on the center board), the machine can be driven to distortion and damage the woofers.

Be careful with the levels especially if one channel seems louder than the other on some records or both channels don't properly fade-up at the beginning of a quiet record.

Rob-NYC

Rob,
Suprizze !! We agree-- Seeburg's seldom "blow speakers"-- but, on the other hand---I can't recall ever seeing/hearing, a TSA 10, that lost all bass either ??
Ron Rich

Rob the External speaker Used was also blown. I ohm that out and it was not working. I have other speakers but not 5 ohms. So I did not bother to try those as they are 8 ohm speakers, and I am not sure if they would work or mess up the amp.

Thanks Lenard

Hi Lenard,
You can use the 8 ohm for testing purposes---
Ron Rich

Ron Rich wrote:Rob,---I can't recall ever seeing/hearing, a TSA 10, that lost all bass either ??
Ron Rich

That sort of thing is pretty common on old solid-state equipment, especially if it hasn't been used for a long time. Electrolytic caps lose a greater percentage of value if left unformed than low value couplers typical in the high impedance tube equipment.

The problem here is that neither of us had direct access to the machine so there was no reliable way to test whether it was amp, speaker or any idea of what the volume control setting was, etc.

At any rate, blown woofers would have been my last guess here.

Rob

Rob,
I really do not recall ever seeing any Seeburg "transistorized" amps, that have lost ALL bass. Agree that the bass will "deteriorate", but there will usually be some response, if they are not open. Ron Rich

Ron Rich wrote:Rob,
I really do not recall ever seeing any Seeburg "transistorized" amps, that have lost ALL bass. Agree that the bass will "deteriorate", but there will usually be some response, if they are not open. Ron Rich

Ron, if this amp uses Output Coupling Caps, they may have deteriorated to the point that they read "almost open"
Then, only highs would be able to pass through them.
Same goes for other caps in the signal flow.
But you know that already, right?

Hi Matt,
Sure, if "couplers" are totally open, on both channels, it could happen--but, I don't think "ZERO sound", from the speakers, would happen in this case, since we know the amp is at least working somewhat. I know I have never seen/heard it happen--?? Ron Rich

I tested it with a pair of speakers and it works great, Thanks for every ones help. I should have my woofers from ebay in a couple days. I am still going to have the amp rebuilt along with the DDC3 in hopes it will last another 45 years. I am hooked on jukes and cant wait to pick up my next juke this week.

Lenard

Ron Rich wrote:Hi Matt,
Sure, if "couplers" are totally open, on both channels, it could happen--but, I don't think "ZERO sound", from the speakers, would happen in this case, since we know the amp is at least working somewhat. I know I have never seen/heard it happen--?? Ron Rich

Ron, it depends on several factors. Since we are talking about bass speakers if there is a crossover it is entirely possible that no treble or mid frequencies will be audible, especially if there are other working speaker (the tweeters) nearby.

A year ago a TSA7 i had on location (in an HVL) went nearly dead on one channel. I hadn't noticed because the load is across the mono 70v. When I got it home there were highs beginning around 2khz, but zero bass.

I do agree that it is unusual for it to happen on both channels. If the external speaker test i suggested had gone well, we would have had an answer sooner. Yet again, the pitfalls of remote troubleshooting.

Rob

Got the right speakers in today and they sound great. Thanks Rob and Ron for everything. I would still be searching the net if it wasn't for great guys like you that are helpful to us newbies..lol

Thanks, Lenard