Threshold FET ten/pc Restore

[DocOct]

I am restoring a FET ten/pc Phono Pre-Amp and I have gone through the power supply and replaced the aging parts. I connected the power supply and listened to the amp only to have one of the tantalum caps fail and smell terrible!! I replaced the tants and the amp is working now. I want to replace the coupling caps and I am having trouble finding the schematic for this unit. Has any one gone over one of these units and replaced the signal path caps? Which are they? Thanks!

 

[Nelson Pass]

The film caps would be fine. If you are replacing caps, do all the
electrolytics and tantalums. The values are not critical, just see to it
that the voltage rating is adequate.

 

[DocOct]

In listening to this pre and comparing it to my tube pre and op amp pre the Threshold sounds very mid rangy and has no extended bass or highs. The problem may not be the film caps but do you know the reason for this? Are the electrolytics in parallel in the signal path?

Thanks

 

[Nelson Pass]

I don't recall any electrolytics in the signal path.

 

[rayma]

The problem may not be the film caps but do you know the reason for this?
Are the electrolytics in parallel in the signal path?

Post a photo of the pcb, maybe it's been "improved".

 

[DocOct]

Do you have the schematic? In looking I can only find the FET ten/HL. Thanks

 

[m2003br]

I'm not a "authority" in Threshold, maybe a applied student, but I think,
If your phono preamp do not have a LF351, possibly the schematic is the same of Forté 40P (schematic attached) or Fet 9 whose service info are on HiFi Engine.

 

[Rossputin]

Hello all,

I'm just getting back to setting up my turntable and associated gear after several years of it (sadly) been in storage.

Thinking about going back to one of my favorite pieces of gear ever, my FET10/PC, after last using a tube preamp.

So my question for you experts, including Mr. Pass if he's willing to respond is this: Should I proactively start replacing capacitors (or anything else) in the unit or the power supply even if at the moment it seems to sound fine?

Thanks in advance for any advice!

Ross in Denver

p.s. Note for Mr. Pass: My amplifier is a T800. Used to be a T800D but one of the meters failed so the people at Threshold recommended replacing the faceplate with the one that doesn't have meters (because they don't have any spare meters). What an incredible amplifier.