can i run my LPC phono pickup into a home stereo receiver?

well, i'm sure i *can*

but will it be a sufficient match? i'm getting distortion... it's probably my TSA--1 which i have yet to recap... but i'm tempted to find a small home-style component phono amp with speaker outputs and run that in the meantime.

i'm actually running a 340D cart on it's proper tonearm and cradle. will the output suit my home stereo, a typical 70's Kenwood receiver?

i'm trying to get my tracking force dialed for minimum distortion before dealing with the lousy amp...

cheers,
eric

Hi Eric,
No problem--any Magnetic input amp should work--HOWEVER, you will hear snaps/pops and other noise as you will loose the mute function, of your amp. You also will need to leave the original amp in place-powered up, to have the ability to "reject" records. Your sub amp must be able to deal with a 16 ohm system--
On the 34x type cartridges-- you will need to adjust the spring pressure to match the type of needles you are using --despite what the aftermarket sellers say "All colors" were NOT the same ! ( See my Seeburg Mech Guide) HTH, Ron Rich

thanks Ron. indeed i encountered the mysterious lack of rejection of any sort when i had the TSA's power unplugged. that one kept me up for an extra hour last night. looking at your timestamp on your reply... are you a night owl like me, or a very early riser?


turns out the worst part of the distortion was due to having the volume control down low while working late at night. the pot sounds pretty crusty down there, crackling and dropping out. today when i bumped it up during waking hours, that aspect cleared up.

probably worth taking the time to recap the amp. it's definitely lacking in highs... it has the interesting midrange compression that reminds me of AM radio. perhaps the limiters are out of spec too.

Hi Eric,
No--I happened to wake up very early yesterday morning--my 80 lb English Lab sleeps with us, and he decided to use my foot for a pillow yesterday morn. This woke me up with a cramp in my leg, so I just got up-made coffee, and hit the 'puter---You could have saved yourself an hour, had you read my mechanism guide, as I point that out there-
As for the amp re-cap--would guess it surly needs it ! You might hit the VC with Deoxit 5--works wonders !
As for the "sound" of a LPC, I believe I also covered this in the guide--IMHO, it is the worst sounding stereo phono ever made by Seeburg--UNLESS, equipped with the "optional DS speakers". Ron Rich

babycat wrote:well, i'm sure i *can*

but will it be a sufficient match? i'm getting distortion... it's probably my TSA--1 which i have yet to recap... but i'm tempted to find a small home-style component phono amp with speaker outputs and run that in the meantime.

i'm actually running a 340D cart on it's proper tonearm and cradle. will the output suit my home stereo, a typical 70's Kenwood receiver?
cheers,eric

Eric, I am a bit confused here, are you running a 340 cart in the LPC-? If so, it will cause distortion and too much bass. These carts have the wrong impedance for that goofy TSA input and too much output. The original cart was (IIRC) a variant of the Pickering 370. Either one will work into an external amp-receiver.

if after the amp is rebuilt the sound is still too dull, one option is to simply add a .1 to .22 capacitor across the emitter resistor of the first transistor in each stage (R103 left R137 right) this will reduce the high frequencies fed back and thus boost them. A .1 will result in only the highest frequencies being boosted. A .22 will move the rising point a bit lower.

Another option is to add an efficient tweeter. Since the system is 16 ohm and most tweeters are 8 ohm, an 8 ohm non-inductive resistor in series is recommended.

Rob-NYC

Eric,
I missed the 340 discussion--are you running a 340, with the later style tone arm/snap-in cart., or a 345 (4 legged) cartridge, on the original style tone arm ? Ron Rich

1st post any i just did that to my 67 hsc while the amp/tuner is in the shop. I'm so impressed with the sound and the fact It plays cds and a cassette AND a remote and fits perfectly in the album storage bin. It will live there for good and if the orig equipment is a tough nut to fix I may put it back and let the dial lite up just for pretty.

Its a Panasonic Sa-pm18 14.00 goodwill special. Not sure my image will post.

Cheers

Alan in mesa az

thanks guys, for the responses! apologies - i hit the road again last week and have been unable to log in.

indeed we swapped the whole cradle/arm/cart assembly for a later magnetic trip type. the tracking adjustment is so easy now! i'm getting a nice 3 grams on either side, and no more distortion from the trip lever towards the end of the records. this set-up is sounding heaps better than the original did with the new T needles.

but yes, i'm still getting a kind of sibilance distortion, mostly on cymbal crashes and vocal sibilance. Rob, what you mentioned seems to be involved. i may get to recapping the TSA-1 when i get home in November, but i was also considering finding a TSA-7 and working with something like that. wouldn't that be a better match for the 340 cart?

would the TSA-7 chassis (or other later Seeburg amp) fit in the LPC amp slot? do they sound pretty good?

the puzzle continues...

What needles are you using ? What color is your new tone arm ?
The TSA 1, and TSA 3 amps are set up for 16 ohm output--all later amps are 5 ohm output. "Swapping" is not recommended. Chassis size is the same-mute plug is not interchangeable. Ron Rich

babycat wrote: i'm still getting a kind of sibilance distortion, mostly on cymbal crashes and vocal sibilance. Rob, what you mentioned seems to be involved. i may get to recapping the TSA-1 when i get home in November, but i was also considering finding a TSA-7 and working with something like that. wouldn't that be a better match for the 340 cart?
would the TSA-7 chassis (or other later Seeburg amp) fit in the LPC amp slot? do they sound pretty good?
the puzzle continues...

Yes, a later amp would be a better match with that cart and generally sound better. ..But creates one new problem that Ron alluded to. The fact that the newer amps were designed for 5 ohm loads means that if used in an LPC w/16 ohm speakers only approx ¼ of the amp's power will be delivered. There is no technical harm that will come from this, but you will lose about 6 db of potential loudness.

I operated an LPC with this stereo retrofit cart in the original amp:
http://s1192.photobucket.com/user/Rob-N ... sort=2&o=5 (same as the later carts) into a TSA-7 for twenty years ending last December. In that installation the main sound came from a line I sent to the house PA. All I needed at the machine was "some" sound. We didn't even use an RVC as level was controlled from the PA board.

There are a few options here for you to consider.

-Replace/bypass the existing preamp in the TSA-1 with an external preamp. This is a simple mod though you will have to pad-down the level from the external pre at the injection point inside the amp.

-A slightly more complicated approach is to transplant the output transformers from the TSA-1 into the later amp. This will work as they both reflect the same load back at the finals and will give the full output to the machine speakers. You'll need to make sure that the feedback wire is connected to the same terminal or a loud "howl" will result -will not cause damage.

- Use the later TSA and simply connect some external speakers to boost and open up the sound. the has the advantage of enhancing the stereo effect and should be done anyway. A TSA 7 is rated to have 32 watts output (it is actually 21 clean) that means a 16 ohm on the 32 terminals would be drawing about 8 watts/ch so you can connect external loads to equal another 25 watt/ch. As i mentioned the real RMS on all these old Seeburg amps is considerably less. the was the Wild West era before the FTC Consumer laws.

- Another option is to use the setup i used at that location and simply feed an external amp from either the high side of the volume control (fixed level) or the arm (variable).

Rob