Problems with Paramount 2A3’s and a Foreplay III [resolved]

[rayrad]

Several years ago I put together a pair of Paramount 2A3’s and a Foreplay III. The 2A3's were later updated with Soft Start Retro kits along with a Foreplay III Line Stage Kit and Extended Foreplay III upgrade. Run Cain & Cain speakers.

Because of a move, the system has been stored in an indoor closet for nearly a year and when brought out put together today, got some low level hissing and intermittent almost inaudible from. Removed and swapped the tubes, sprayed some electrical contact cleaner; made no difference. Based on past experiences, assuming the problem is with the Paramount's.

Have attached voltage and resistance measurements from one of the Paramount's. The 2A3's a couple of years ago but the remainder of the tubes are original. Help . .

 

[Paul Birkeland]

Can you let us know how you came to the conclusion that the Paramounts are the issue?

You've posted the same PDF 3 times, and that looks like a working Paramount.

 

[rayrad]

Good question. Guess I am blaming the Paramounts because over the years I have had several problems with these. Never had an issue with the Foreplay. One tract mind. Found my old Extended Foreplay Manual and on pgs 42 & 43 found the chart for e/r's. Will take Foreplay measurements as well as the other Paramount and send them on. Getting withdrawal symptoms.

Any other suggestions??

Yeh, out of ignorance, I sent 3 copies for the same unit.

 

[Paul Birkeland]

Is the noise you're hearing in both channels? (decent indicator that it's the Foreplay)

To sort out which component you need to mess with:

Short the input to each Paramount.  You can solder a wire temporarily across each RCA input jack on the amp.  Now run the amp into your speakers.  Do you hear the noise?  If so, it's the amps, if not, it's time to look at the preamp.


-PB

 

[rayrad]

Just ran the these tests last night and it looks like most of both amps measurements were close to design specs. You already reviewed both 'Actual 2' columns.
Many of the preamp measurements though; much to my chagrin, are way off.
See attached tests.
And yes, I was getting a hum from both speakers.
After looking at my test results you still want me to run the short tests, will do

 

[Paul Birkeland]

How does the center board in your FP-III look?  Has it turned brown, or is it still about as green as the other two?  Does it have MJE-350's, or MJE-5731A's (5731A's will look bigger than the 350's).

-PB

 

[rayrad]

Thanks for your quick and thoughtful response

The centerboard has the same green look as the other two. No apparent anomalies.

Looking on the parts list it indicates thee are 2 ea MJE340's and 4 ea MJE350's; that accounts for all the MJE's

Everything looks normal on the underside

See attached photos

 

[Paul Birkeland]

The center part of your center green board shows the cooking that can accumulate over a long life on the E-FPIII.  We tweaked things a bit eventually, using a fatter transistor that was much happier to deal with the heat (even though the MJE-350 is "rated" to do what we wanted it to).

Consequently, I am more than happy to repair that for you under the flat rate repair, or for $50 I can make you a replacement center PC board that you can install on your own (with the new parts).

-PB

 

[rayrad]

OK let's see if I understand it correctly:
1) You make me a replacement center PC board with all new parts, ship it to me and I send you fifty bucks? Sounds like a good option and easy for me to replace as it looks like there are just 9 wires to connect.
2) I send you the E-FPIII, you install the completed board, return it to me & I reimburse you the flat rate repair fee?

If it is as simple as that, I go for option 1. It sounds like you are reasonably sure the culprit is that center PC board. My question is do you think it would be beneficial for you to have the unit for further diagnosis? I guess if I still had a problem, we would deal with it then.

So if this banter holds up, I'll give you my CC information and you go ahead make and ship the PC board.

Any further thoughts on this?

 

[Paul Birkeland]

Yeah, since your name is in your signature (thank you!), I'll have Eileen get a Paypal invoice to you today and get the board built for you.

-PB

 

[rayrad]

Thanks for the fast turnaround on the Shunt Regulator Board. Other than some of its components look differently, noticed that some of the jump wires are connected differently. Took the old board off and intended installing the new one tonight. Problem or maybe question is when I went to the insert the black wire of the TTP; both A & B sides of the board, the intended second port down on the left was occupied by a jump wire from underneath (see last two instructions on the original manual if you were to have it). What to I do boss??

 

[Paul Birkeland]

Took the old board off and intended installing the new one tonight. Problem or maybe question is when I went to the insert the black wire of the TTP; both A & B sides of the board, the intended second port down on the left was occupied by a jump wire from underneath (see last two instructions on the original manual if you were to have it). What to I do boss??

There are a bunch of pads on the board marked with "-", which are all connected.  The "G" holes are also connected to these holes.  The black wire from the TTP just needs to solder to one of these open pads, and an open "G" pad is probably the easier option.

-PB

 

[rayrad]

Thanks for clarifying. So upon examining the new board you sent there are 3 "G" holes midway down each side of the board next to the "R2" resistor location, one of which is empty. This is where I install and solder the TTP wires? yes/no

 

[rayrad]

Bingo! Thanx so much . . sure have missed my sounds

 

[Paul Birkeland]

I'm glad it's all back up and running!  The new components on those boards ought to last well past the 20 year mark.

-PB