Someone (in here) recently wrote that 'knowledge is the devil'.
I find this to be true when it comes to low-fidelity wives and high fidelity amplifiers.
The first problem has been solved (no, she is still alive), but the second is a bit more difficult.
I happen to be the (very) happy owner of an early Threshold S/150.
However, I recently stumbled across a document (attached) that in fine detail describes what my amplifier does NOT sound like.
Very disappointing, especially since the first problem has left me unable to simply buy something better, so... dear pa... could you please
A: Send more money.
or
B: Search the most remote storage-spaces for a pair of (un)populated opto-boards.
or (considering the amount of Zen, F, BA and Aleph-variations that has emerged over time)
C: Design a schematic for the 'Stasis Traps' (To Rule All Previous Stasis).
I would seriously love to have my S/150 sound better than my friends SA/2's.
PS: Forget about A. The b***h takes half anyway!
I find this to be true when it comes to low-fidelity wives and high fidelity amplifiers.
The first problem has been solved (no, she is still alive), but the second is a bit more difficult.
I happen to be the (very) happy owner of an early Threshold S/150.
However, I recently stumbled across a document (attached) that in fine detail describes what my amplifier does NOT sound like.
Very disappointing, especially since the first problem has left me unable to simply buy something better, so... dear pa... could you please
A: Send more money.
or
B: Search the most remote storage-spaces for a pair of (un)populated opto-boards.
or (considering the amount of Zen, F, BA and Aleph-variations that has emerged over time)
C: Design a schematic for the 'Stasis Traps' (To Rule All Previous Stasis).
I would seriously love to have my S/150 sound better than my friends SA/2's.
PS: Forget about A. The b***h takes half anyway!
Hi Baeijsman
Congratulations, it's collector, vintage amp in 2018.
Do You have always the same old power supply electrochemical capacitors inside?
If yes change them maybe for new ones is little effort to do and can bring sonic benefits and longer service time. Diy it
Attachments
Hello baeijsman.
The complementary symmetry "STASIS" power output stage is a highly respected voltage follower [VF]. The voltage source amp [VSA] which drives it in the 1982 original S/150 THRESHOLD power amp [I own] practices [with VF] the teachings of the Pass Patent US 4,107,619. This particular VSA is high caliber because its gain BJTs are cascoded as taught.
I was given the opportunity [then by THRESHOLD Corp] to upgrade its VSA to Series II. I ignored the offer because the original sounded great then, and still does now as is.
I recently augmented its original power supply by adding an external bank of 25,000uF/75 V capacitors per power rail. It restored the original oomph! to its bass.
Best
Anton
The complementary symmetry "STASIS" power output stage is a highly respected voltage follower [VF]. The voltage source amp [VSA] which drives it in the 1982 original S/150 THRESHOLD power amp [I own] practices [with VF] the teachings of the Pass Patent US 4,107,619. This particular VSA is high caliber because its gain BJTs are cascoded as taught.
I was given the opportunity [then by THRESHOLD Corp] to upgrade its VSA to Series II. I ignored the offer because the original sounded great then, and still does now as is.
I recently augmented its original power supply by adding an external bank of 25,000uF/75 V capacitors per power rail. It restored the original oomph! to its bass.
Best
Anton
Hello Antoinel
I bought a pair of Cornell Dubilier 37.000uF/75V when I recapped mine.
Same size as the originals, so easy to fit! ...and good!
I will proceed with the Speaker/Rail fuse conversion in the near future.
Thank you baeijsman for the above valuable info. I prefer to keep the rail and speaker fuses and replace the originals [still in my S/150] with new/same valued ones. Their presence was a good faith/wise move by Pass at Threshold Corp. to protect our expensive amp [a brute] and loudspeakers.
Antoinel:
TBH, part of me feels it's a kind of sacrilege to even take the lid of one of these, but... the change to the fuse/wiring was done by pa himself, and as long as he is holding the wheel, I don't mind tagging along.
Besides... I think the amp itself is actually better protected with the xtra rail-fuses.
TBH, part of me feels it's a kind of sacrilege to even take the lid of one of these, but... the change to the fuse/wiring was done by pa himself, and as long as he is holding the wheel, I don't mind tagging along.
Besides... I think the amp itself is actually better protected with the xtra rail-fuses.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.