2003! Very impressive and huge heatsinks to cool down those outputtransistors.
The Blue BC psu caps were used by Levinson in their 300 series (331 trough 336) and were troublesome I remember.
They had to replace them all I believe.
Still playing everyday for 20years now. Had to change the transformers and the caps early on because the voltage was too high.
The caps here in the pictures are Panasonics, don't remember wich one.
The caps here in the pictures are Panasonics, don't remember wich one.
speaking of motor runs
100uF is pretty much same size as 50uF, while price isn't doubled
what I meant, just be sure we're on same page, if you think putting less than 50uF motor run caps, do not even bother
if you think of less than 50uF, feel free to use some in more convenient/nicer looking case, which also wouldn't invoke your audiofriends making fun of you
me - I don't care - don't have audiofriends
of course, if you want ultimate, buy few '' of thin wall brass tube, put each of your motor-run caps in appropriate piece of tube, shiny it up, conceal solder lugs with some fancy wire, write Obligahaha on it, clear coat
you'll be main Boss
you can also use magic words as WE, Beeswax, Cotton, Virgin Pee
Well the proof is in the pudding. Great that you still have them. Are the BC's 3 inch diameter ones?
Okay, that's 2 inch.
If they were 3 inch with the clamps suited for it you could buy the same 100,000uF 80V CDE's as I bought for my SA/1's.
But seems you're pretty satisfied with your current setup so there's no need to...
That's common sense.
I replaced mine as a precaution and those sizes (the ones I needed) are nowadays very hard to get or you have to order them in bulk (over 24 or so) or they are very expensive. So I saw an opportunity for a decent price and they were on stock so I bought them.
NP stated they if they service power amps they (recommend to) change the psu caps if they're older than 20 years. Mine were 35 years so I changed them but they're still good as you said.
....
Another thing is that's there no softstart circuit implemented in my SA/1.
I bought this thermistor:
Ametherm MS35 10 ohm 18 Amp Inrush Current Limiter to put where I always see CL60's in schematics of Aleph amplifiers.
Not for surpressing groundloops of course, but TH2 in this case.
These are thermistors too I believe in a SA/10/11M
I bought this thermistor:
Ametherm MS35 10 ohm 18 Amp Inrush Current Limiter to put where I always see CL60's in schematics of Aleph amplifiers.
Not for surpressing groundloops of course, but TH2 in this case.
These are thermistors too I believe in a SA/10/11M
When I changed the power supply (early on) I used a lower voltage transformer, the BC caps and hardwired them CRCRC. Another change was made by replacing the point to point circuit with a 'real' PCB and added a cover on top of the amps.
Softstart with thermistor is a good thing. Nice implementation of the new caps. In (older) PA amps with TO3 I always tighten the screws of the transistors. Of course this Threshold has never been on the road.
Looks very need and tidy especially for a DIY Aleph version..
Why did you choose those golden powerresistors with heatsinks? Do they become hot in a CRCRC implementation? Normally I see those in a softstart circuit.
Got these from the original owner who drove his Infinity RS1b's with two pairs. They came even with the original cartons.
They are 0,1 ohm 10W resistors and mounting them on the ground plate makes for a good heatsink. They get hot. The bridge rectifier is also mounted on that ground plate which adds up to the heat. Downside is that the caps absorb part of that heat. But they never complain..
Yes, that Threshold looks like new. What speakers are they driving now?
Haha, they wouldn't dare...
Infinity QLS's. They don´t complain either about the load and low efficiency...
This user (https://www.diyaudio.com/community/threads/brand-new-threshold-sa-1-pair-from-1988.385741/) scored some NOS Threshold SA/1's, black fascia's also. These were really pristine.
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