Forums - Print Page

Forums
https://www.decware.com/cgi-bin/yabb22/YaBB.pl
AUDIO FORUMS >> General Discussion and Support >> Fuse Board
https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1596394130

Message started by piezoman on 08/02/20 at 19:48:50

Title: Fuse Board
Post by piezoman on 08/02/20 at 19:48:50

My Taboo has a fuse board mounted underneath, the purpose is to protect the amp from damage in case the rectifier suddenly fails. It contains 3 fuses.

Not all the Decware amps have this provision. Does anyone know the background as to why this extra protection was added in the circuitry? I would guess up front the fuse located on top at the IEC / power cord would be sufficient as it is for example the Torii MK 4.

Also.....when we upgrade fuses for audio quality in our Decware amps, we replace the one at the power cord. For the Taboo, does anyone know if the 3 fuses on the board underneath also need upgraded, or are these out of the path enough to ignore? If these couod stand upgrading, that could be an extra expensive proposition.

Title: Re: Fuse Board
Post by CAJames on 08/02/20 at 22:24:47

I can't speak to the Taboo in particular, but in general it is hard to imagine a component further from the signal path than the mains power fuse. So if it is worth upgrading I would assume all the other ones are too.

Title: Re: Fuse Board
Post by will on 08/03/20 at 00:02:44

I think the fuse board presence is probably more about newer versus older amps. I recall seeing a pic of a Torii IV with rectifier fuse boards. But my Toriis, being older, do not have them, the IEC fuse breaking when a rectifier shorts.

I would assume similarly to CAJames, since IEC fuses can be heard, it would seem the rectifier fuses could make a difference too. In my amp work, I got to a place where it was hard to differentiate signal path from power parts and paths in terms of the sonic effect. Changing about anything in there makes a sound difference to me, especially with the right parts changes. Associated, to me, changing power supply bypasses, brand, types, and values, can be heard similarly to changing coupling caps.

I don't know how those boards are organized though, what fuses are used, and how they might effect the sound individually and collectively..so can't comment on that without experience.

Hopefully Steve and others who have played with these fuses will comment.

But in the meantime, I might be inclined to just play with the IEC first anyway, and see if you like what you hear. Also if you are not careful and familiar with them, opening a tube amp can be dangerous, while possibly effecting your warranty....

Title: Re: Fuse Board
Post by piezoman on 08/03/20 at 00:30:08

thanks guys, for your input so far.

opening up the amp is no problem. all you need to do is discharge the power supply capacitors to deal with any appreciable voltage remains after shutdown.

i used this as a guide: https://www.youtube.com/watch?v=sw9KnSFy3Fs

this is also useful: https://www.wikihow.com/Discharge-a-Capacitor

Title: Re: Fuse Board
Post by piezoman on 08/03/20 at 00:59:23

i wonder what that minty green goop is that appears to be coming out the seams of the two black caps :o

Title: Re: Fuse Board
Post by funch on 08/03/20 at 03:00:30

The pic links just lead to a sign in page for dropbox.

A leaking PS cap isn't a good sign.

Title: Re: Fuse Board
Post by piezoman on 08/03/20 at 16:13:58

Thanks funch, I'll post them up differently very soon.

As for the apparent "goop", I opened up the amp again and upon closer inspection, is just globs of glue to help hold the capacitors together. Upon some research, this is a common practice with mfrs. and some folks like me mistake the minty light green glue for a physical leak. A true leaking capacitor oozes brown/tan/whitish discharge that gets crusty.