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Trying to finalize my resistor mfg selection for a power amp I am building. The BEAST from TranscendentSound.Please advise on the following selection, appreciate your input.
1) Riken ohm Tantalums for resistors in the signal path: 1/2 Watt
2) resistors <=1 Watt, considering the Vishay RN65D for my 1/2 Watt Metal Film resistors
3) 2 Watt Resistor - found Vishay CPF2 Metal Films with a tolerance of +/-5%. Would like a resistor value with +/-1% tolerance however.
4) 3 Watt Resistor?
5) 5 Watt Resistor - 2.5 Ohm and 1K Ohm, the Mills MRA5 non-inductive wirewound looks good. The Ohmite AudioGold look good, but I could not find a supplier. Do I need a high quality 1k Ohm resistor for a connection to the fuse?
Thanks
JimThe Dayton Wirewound looks good, but they did not have the values I was looking for.
Have you come across Kiwame resistors?
Any other suggestions?
Follow Ups:
Don't seem to be our favorite things:)The dale/vishay RN series are good enough. Mills makes a very nice wire wound but other brands aren't bad. Just stay away from the "white monkey coffin" types. Mix and match. A carbon film here, metal film there, and a few wire wounds when you need the wattage. Stick with high quality low price parts. Then after it is built and settled down sub in a boutique resistor one location at a time and see what you hear.
Anything greater that 3-4 Ohms is LOW FI!!! ;-)
YOU were present, right in the room with us Ivan, listening to our latest ( just last weekend ) power supply experiments on Greg's 245 SE amp's output stage's B+ !!Reported below.
Rodney Dangerfield
A question that is totaly unrelated to power supplies winds up as a forum for Jeff's ideas. Please stick to the subject at hand!!!
The L1 went from 4HY to 35mHy, what did you do to keep the B+ voltage the same as it was when you started? And how do you know if the difference you heard is caused by the steps you took to keep the B+ the same. Or if you did nothing to keep the voltage the same, how do you know that the difference you are hearing is not the difference in the voltage. Jeff, your report is full of holes.Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Why hello Tre',So nice to hear from you.
We started with two seriesed-connected Signal Transformer Co. DU-1/2s, ... do you know what that PT is? It has FOUR 104-110-120 VAC windings, two on the primary and two on the secondary of each trannie. Lotsa' voltage combinations are possible !!
Tre', why OF COURSE voltages were the same !! I measured them carefully to protect the vintage 245 ( and do a fair comparison ), measuring with my Fluke 8060A when doing all changes!!
We really can't deny the clear-cut sonic superiority of this output stage power supply approach over "conventional" L-input filters, etc. as promulgated during the last 100 years. On Greg's RCA Field Coil /Altec 515 B system, it is startlingly wonderful.
Your report should have included details regarding how the voltages were kept the same. Will you tell us the details now?Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
The answer to your question was already quite clearly inferred in my above response!1) multiple tap combinations on the Power Transformers and
2) Fluke 8060A
The only one being "guilty" is you. I am cool here, you are the one "guilty" of being a total jerk about this report of mine, Tre'.
BTW, the Signal DU1/2 PTs must be under 3 to 4 ohms each in DCR. Rated 500VA !!
Mr. Swenson uses 'em sometimes too.
:-)
There is no detail in this report. What primary taps were in use to start with? What primary taps are in use now?As far as "Innocent, until proven guilty, the norm in America", that is for criminal cases. In science, you are wrong until you prove yourself right.
Now please give us the details of how you kept the B+ voltage the same after making those changes in the power supply.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Tre',With two different Signal Transformer Co. DU 1/2s in series,( as Greg and John Swenson use them ), there are four windings on the primary and four on the secondary. Each winding, however, has four access points at O-104-110-120 VAC.
So, there are a multitude of combinations possible - because you have 4 windings times 3 ( not 4 ), or 12 taps on the primary and 12 taps available on the secondary. The VAC combinations obtainable, with 12 primary taps and 12 secondary taps are truly VAST !!
It is not of import "one iota" as to what exact taps were selected, as long as the overall B+ voltages were similar - as I had intially reported. They were similar BTW, at under two percent in difference as we recall. So, why "invent in your mind" - such an obnoxious smokescreen, that MY method is not sound? That is pure B.S.
All you are doing is (1) existing in denial and (2) trying to discredit me publically with one of the silliest things I've ever seen you profess up on AA. You need some help!!
What you SHOULD be considering in your mind is the findings of our subjective listening evaluation : that the Low HY, Low DCR, Low C approach ( as developed by my friend, the designer of Serious Stereo 2A3 SE amplifier) TOTALLY SMOKES conventional audio power supply implementations, which have been regularly used over the last 100 years.
I am open-minded - as to whats the best sounding power supply implementation and I wanna USE it for my listening enjoyment, and make it available up here to others who may share a similar interest in great sound. That audience doesn't seem to be you, and frankly, thats perfectly OK by me.
Jeff, you still have not told us what taps were and are used or what the secondary voltages were and are. I don't buy your "under two percent" BS until you tell me the details.Your opinion is your opinion, you are welcome to it but the facts surrounding what you report have not been disclosed. And until they are, no one can make sense out of what you have reported.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Well,..... here is the email I find in my home mailbox:From:
To: "Jeffrey Medwin"
Subject: "you are the one "guilty" of being a total jerk about this report of mine, Tre'."
Date: Mon, 26 Feb 2007 16:46:09 -0800Don't call me a jerk you bastard. If you are going to publish reports
about your silly Low DCR, Low H, Low C shit, make them scientifically
complete or keep them to yourself.
I will call you to the mat every time.
Tre'
- - - - - - - - - - -
Tre'I don't post on AA to please you!!
If you don't believe me, just take a long walk off a short pier.
If you don't make full disclosure of your technical process you have no
credibility.It's not about me, Jeff. It's about truth.
Tre'
P.S. I stand by that email. You always make this personal(name calling, etc...) because you can't back up your BS. Why don't you come to California and we'll talk about it?
Have Fun and Enjoy the Music
"Still Working the Problem"
Bull. What taps I select make NO difference, if the final stage's voltage is within 2% or less !! Any idiot knows that.I don't need to answer smokescreens to the likes of you on such a silly, no, sutpid psuedo-scientific question. Reasonable questions I will answer.
Your HEART is in the wrong place and you are mentally and emotionally off-base on this .
You certainly do TOTALLY miss the larger aspects of the information I provide!! Things like "critical inductance at 60 HZ" is sonically UNdesireable and to be avoided at all costs. You can't accept it, as it is COUNTER to whats in your beloved RDH-4 and how you believe to build.
Re-read RDH-4 on audio power supplies, while I spend time enjoying Greg's amp, as it is now playing back music - like NEVER before !!
Jeff Medwin
My favorites are IRC GS3 for up to 3 watts and IRC RN60D for .5W. They are available from Handmade Electronics (https://www.hndme.com/productcart/pc/viewcategories.asp). I tried Riken carbon films, but found them too bright for my tastes (and insanly expensive).
IRC is consistently recommended as a high quality/value resistor.Hand Made has been identified as a source, are there other suppliers I can source from as well due to limited selection.
for Mills, Vishay, and Kiwame resistors
I have had no luck with Michael Percy. Long delays followed by emails stating that he could not fill the order due to the high volume of business.Have things improved lately ?
Diyhifisupply
"...In research as in life one is far more likely to find what one looks for than what one neglects."
-The Modern Researcher; Jacques Barzun & Henry Graff
Harcourt Brace Jovanovitch, Inc. third edition 1977
"To be thus is nothing, but to be safely thus" William Shakespeare.I am persuing the safely thus - please provide sage advise and wisdom on resistor recommendation.
Some of the non-inductive resistors are going into the output stage - I understand that in some cases it is good to have inductance in the output stage. Also, the amp has a negative feedback loop - should I be sensitive to what resistor are used?
'Also, the amp has a negative feedback loop - should I be sensitive to what resistor are used?'Possibly the most critical resitor in the entire amp: use high quality non-inductive.
My favourite by far in this application is the Caddock MK132.
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