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August 6, 2015 - 12:09pm
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Seemingly easy Amp question
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The original unit had a 12 ampere mains fuse for the AC, and four 7 ampere fuses for the + and - DC power rail of each channel's power supply, all located in the rear center area.
When you say "pop-out type", that sounds like circuit breakers rather than fuses.
Someone may have added those for convenience; are there four of them, and what are they rated at? These normally must be "fast-blow" fuses; slow-blow or circuit breakers will cause sonic degradation.
There could conceivably be some sonic degradation due to putting the wrong type of fuse or circuit breaker in series with the DC power rails. One would have to know the detailed technical specs of the particular fuse or circuit breaker, and choose very carefully.
I have experimented with amplifiers and found that a fuse can act as an excessive variable resistance (which is what a fuse must be to unction...a variable resistance) that affects sound quality.
In one case, I found that the manufacturer had put 8 ampere fuses in the DC rails at the factory, to be conservative, when in fact 12 ampere fuses were more appropriate and sounded markedly better.
circuit breaker...
I have to correct my statement (I did not recall correctly)
.. It has four of these.
once or twice over the years one of these has tripped
I've used this Amp for my NHT ST-4's for >10 years now
but to add an amp it looks like I may run into trouble
photo:
http://www.stereophile.com/content/fuses-adcom-gfa-555#aB04llSUEduVGpwd.97
I would strongly advise you to remove the circuit breakers and replace them with fuse holders.
8 ampere fast-blow fuses should improve the sound quality.
Thanks commsysman
Do you have a product recommendation / relative instructions for this? (btw - ceramic or glass?)
Standard glass fast-blow fuses are type AGC, as AGC 8.
DelCity sells an AGC chassis-mount fuse holder for $2.35 each; part #79075.
Thanks for the suggestion, the fuses are on their way. I haven't figured out how those breakers come out yet, as I've never worked with a mounting mechanism like that before but I'll figure it out, if I have to break them off (no use for them)
Hello. Well, I am onto the replacement but the terminal on the wire is too large for the connectors on the back of the fuse. They won't hold together. I don't have the knowledge or equipment to get into the soldering job of replacing the wires for wires with matching terminals. Is there an adapter of some sort that I can get? Are there AGC's with the right size terminals?
Thanks.
(without sound at the moment, as the re-circuits were super glued on and had to be busted up and removed piece by piece. help!! :-) )
[[Just to elaborate]]
It looks like the connector type on my wire is a "Insulated Female Spade Connector"
The size on the wire is not correct for the "male spade connectors" on the back of the AGC fuse holder.
Short of replacing all of my wires, which involves quite a bit of soldering, for which I am not equipped - any suggestions?
It looks like I'm going to need to "replace the female space connectors to match the terminals"
If I have another, simpler option, I'd be grateful to hear it.
Looking for advice here, please.
The female quick connect spade which connected previously to my re-ciruit (circuit breaker) is not a fit for my new AGC fuse holder.
But more than that - I cannot find ANY size female quick connect spade that fits it.
Does someone know the appropriate connector for this scenario?
image of quick connect and fuse holder terminals:
http://www.stereophile.com/content/female-quick-connect-spade-will-not-fit-agc-fuse-holder#1TwzYaHs4FZfuQHq.97
Well, I got this done. I didn't understand that the 22-10 measurements of a quick connect are not about the width of the terminals. The width I needed for the AGC fuse connectors was .187 (purchased 3/16" female spade connectors)
So far I have lost the crackling and loss of one speaker that would come and go when the re-circuits were in place (a few more days will tell for sure). Also there seems to be tighter base response, improvement in mid-high clarity and volume but it's hard to be sure. There is less hiss at silent periods for certain. Shine on you crazy diamond.
Thanks commsysman.