Anything wrong with Treshold "T" series??


Was told by a dealer that if I was interested in a used Threshold go for a earlier "S" as opposed to latter T series as something went wrong on latter ones.Anybody know what I am talking about?Or he was talking about?
chazzbo
The "T" series makes use of output devices that are no longer available from what i understand. Having owned several amps that made use of similar circuitry with the same devices and pounding on them day after day, i would not worry about this too much if you like the amp. Just pay attention and be careful like you would with any other electronic component. Sean
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Sean is correct. The T series used IGBT transistors which is a cross between bipolar and MOSFET. I think Toshiba and International Rectifer used to manufacture them but not anymore.
Hi Chazzbo,
I've not heard of any problems with the T series. I could be that the dealer is a Nelson Pass design fan, and is just somewhat biased against the T, which Nelson was not involved with. Jon Solderberg of Vintage Amp.com you tell you more if you have a specific question. Like Sean, I have an S350E (inbetween the S300 and S550E), and a FET 10E pre. They are excellent, and I highly recommend them. There is a very clean S300II on eBay right now for an attractive price, but I wouldn't be afraid of a T. I do think you can get more amp for the $ with an S, as they are older. Log on to Vintage and ask Jon about the amp you are looking at. Tom
Sean is correct - the Hybrid FET-bipolar output stage (IGBTs) is no longer available, though I believe the new Threshold Audio, Inc. will bring select T-series up to current spec(for a price, of course). Jon Soderberg also works on vintage Threshold amps and will also work on the T series, though that might entail swapping out the IGBTs for a traditional output stage.

In any event, the T series was terrific, particularly the T200 - I've got one myself. They are indeed built like tanks, but nothing lasts forever...

If the price is right, go for it!

Jim
The "new" Threshold Company out of Houston, TX. wants nothing to do with the older "T" series amps. I recently had a nice long phone conversation with Mr. Curtis (Thresholds current President) and either he doesn't know about Jon Soderberg or was unwilling to let me know Jon's services were available.
I can tell you that Jon Soderberg has a T-100 in his home system.
The T-100 is the model which would have the biggest draw backs for the reasons others have stated but Jon assured me that he's never received a Threshold amp that he returned because he was unable to fix it.
The reason I know all this... I've owned a T-100 since Feb of 1994 and thought technical difficulties were being experienced and began the search for a reputable repair shop.