2. amps-preamps
  3. 149021-78302

Threshold FET Two - Manual or advice for MM/MC phono setup?

I recently acquired a Threshold FET Two (series I) without a manual.  I have questions about the MM vs MC phono setup.  On the back there is one set of phono RCA inputs, and one capacitance switch to select between 100pF & 300 pF. Is it necessary to open it up to set jumpers/switches for MM vs MC?  Or is it self-adjusting?

If curious, it will be fed by a also recently acquired Denon DP-790 (circa '75-79?) with stock arm.  Cartridge still TBD, but it has an old (entry level?) Grado GT at the moment. 

Any help or comments would be appreciated. 

Also, anyone have any idea where I can get or download an Owner's Manual (and/or Service Manual)?

Thanks in advance.
spenrock
millercarbon's avatar
millercarbon
12,531 posts
 
Well none are self-adjusting. On-line images show phono inputs labeled as ANALOG DISC PLAYER. The two switches to the left are labeled CARTRIDGE TYPE and (further to the left) CARTRIDGE LOADING.

MOVING COIL obviously is MC but their label is a little confusing if you don't know that FIXED COIL is the same as MM. 

If this is your panel then flip it down to MM (FIXED COIL) for your Grado. (Pretty sure being Grado your GT is MM.)

It seems there are a couple versions of this, not sure which yours is. But if you see pF that is pico-Farads which is capacitance and applies to MM. If you see Ohm with something like 100, 200, 50 that is to adjust MC loading. If one or the other is missing then you don't have that option.

As far as a manual goes, have you tried Duck Duck Go? Or any of them. Just not Goolag. Please just never use Goolag. Thanks in advance.
spenrock OP
24 posts
 
Millercarbon, thanks for the info.

My version is the series I, so it only has a single selector switch. After reading your post, I realize it has three positions: A) 100pF; B) 300pF; C) 1k Ohm.  Therefore, I assume two positions for MM, and a single position for MC carts.

I will try a deeper dive looking for a manual using DuckDuckGo or other engines.

Cheers
unsound
7,329 posts
 

You might want to try:

http://www.threshold-audio.com/

http://www.vintageamprepair.net/

https://www.passlabs.com/

https://www.diyaudio.com/forums/pass-labs/

spenrock OP
24 posts
 
Thank you for the suggestions unsound.  I'll try these as I keep searching.  I just thought, maybe a FET Two series II manual will have reference to series I, so it might work also. 

By the way, just fired up the Denon TT and the FET Two today.  First impressions are far beyond my expectations.  More than happy!  If it improves further with a new cartridge, going back to vinyl is completely worth it.  Actually, already is.
More to discover