I'd like to have the anti thump feature, I think you need a separate supply for that.
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Why degrade what is a superb-sounding amplifier by using just the one SLB PS?
Great question, would a stereo build of this amplifier with a single transformer and slb power supply significantly degrade the sound? I’d love to hear more opinions on this as I plan my build!
Maybe “degrade” is too aggressive of a description.
Having built a few amps, the dual mono power supply builds have the quietest background and slightly better stereo imaging in my subjective opinion.
You can build a Fantastic AN with a single supply! But, if you have the extra $$$ and chassis space to fit the dual supply it’s something to think about.
Or….
Initially build with a single supply keeping in mind the thought of “upgrading” later to dual mono supply.
Having built a few amps, the dual mono power supply builds have the quietest background and slightly better stereo imaging in my subjective opinion.
You can build a Fantastic AN with a single supply! But, if you have the extra $$$ and chassis space to fit the dual supply it’s something to think about.
Or….
Initially build with a single supply keeping in mind the thought of “upgrading” later to dual mono supply.
Thanks for the info @Vunce, very helpful.
Would two of the transformer below work with the R2R rectifier boards? I imagine I would need the extra winding for both channels… I didn’t see a 300VA 24v with the extra secondaries.
https://www.antekinc.com/au-4424-400va-24v-transformer/
Would two of the transformer below work with the R2R rectifier boards? I imagine I would need the extra winding for both channels… I didn’t see a 300VA 24v with the extra secondaries.
https://www.antekinc.com/au-4424-400va-24v-transformer/
Yes, dual mono is recommended for lowest noise floor and getting it hum-free.
All the latest amplifiers that I've built are dual mono.
Learned it the hard way: an amplifier that I had build with a shared transformer had an annoying hum,
tried to get rid of the hum, didn't succeed, until I finally made dual transformers PS and it became hum-free 🙂
All the latest amplifiers that I've built are dual mono.
Learned it the hard way: an amplifier that I had build with a shared transformer had an annoying hum,
tried to get rid of the hum, didn't succeed, until I finally made dual transformers PS and it became hum-free 🙂
I read through this last year while building an amp, really a great wealth of information here in wiring an amplifier for zero noise. In particular the last section with practical tips and routing the audio input wires for reduced ground loop area. I found it very helpful.
https://hifisonix.com/wp-content/uploads/2019/02/Ground-Loops.pdf
https://hifisonix.com/wp-content/uploads/2019/02/Ground-Loops.pdf
Hello all, quick question on resistor choice for R124, R126, R143. They were spec'd as Carbon comp 1w. I read in posts 3074, 3075 that @Vunce recommended carbon film since the carbon comp were out of stock at mouser. The recommended parts in that post are 1/4w. It looks like the carbon comp were spec'd at 1w. Will the 1/4w work in this position? Any help greatly appreciated. Thanks!
Hello,
-R124-R126 carbon film-1W
-R143 metal film-1W
Regards
-R124-R126 carbon film-1W
-R143 metal film-1W
Regards
I can supply some, if you can't find an adequate alternative. Bought from RS Components - so they are genuine!
You can still by the OnSemi version of the 2SC3503E at Rochester. I have some I got from there if you want to PM me. The "E" grade has higher hfe anyway.
The issue with ordering from Rochester is that they have a $250 minimum order amount. Otherwise, it's a very reputable source for legit parts.
And Profusion in the UK sell the equivalent which has tested good and straight swap I believe. They will send to the US cheaply enough aswell.
https://gb.profusion.uk/uk/ktc3503-y-u-ph
https://gb.profusion.uk/uk/ktc3503-y-u-ph
Yes good point jimk04! I recently procured a bunch of KEC parts from Profusion. The KTC3503-Y measured very consistent (hfe=140, Vbe=0.730V) and KTA1381-Y (hfe=130 Vbe=0.720V) [I measured 60 qty of each with an Atlas Peak DCA75Pro]. Also a really good option if you consider the $40 shipping cost to US. I ordered a large qty if anyone in US wants some pairs for cheap.
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birdbox
to get closer values i personally "warm up" -lamp - the transistors to get real enviroment like in the real amp. ;-)
chris
to get closer values i personally "warm up" -lamp - the transistors to get real enviroment like in the real amp. ;-)
chris
The "lamp" warm up is a great idea. I used a different tool with the same approach for matching MOSFETs: I have a hot plate that controls temperature pretty well and I set the temperature to match what I think the operating temperature of the FETs will be on the amp heat sink (typically 50°C) and measure Vgs (with a 6.5 digit desktop DMM) at that temp and assumed voltage/amperage (24V/1A bias) for each FET. Here's what it looks like in action...
I suppose I could do the same thing with the smaller BTJ's at a lower temperature. What would they be expected to run at? I would love if someone shared a temperature measurement of the C3503 parts while in operation on the amp.
I suppose I could do the same thing with the smaller BTJ's at a lower temperature. What would they be expected to run at? I would love if someone shared a temperature measurement of the C3503 parts while in operation on the amp.
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That's all very commendable but, surely, if you are trying to match some transistors' Hfe (or whatever) ... then if you select 2 which are matched at room temperature (say, 21 deg C) - they will still be matched at the amp's operating temperature (say, 50 deg C)?
Although, of course, their readings will be different (higher?).
Or can't we assume that the transistors will have a uniform temperature difference.?