Dynaco SCA-35 - fan Cooling?

[bulgin]

Hi All

I have a Dynaco SCA-35 which is still bog standard other than a thorough cleaning when I bought it, a repaired balance control, a new power lead, all original tubes etc. I have resisted any further mods (other than replacing the on/off switch and changing the amber lens for blue) for now as it still sounds so good (I know, I know)...

I have a couple of quiet fans here doing nothing. Do you think if I rig one of the fans to extract hot air from around the hot running components, I will prolong the amp's tubes and current performance? Will this arrangement do any harm?

Cheers

bulgin

[DualTriode]

Originally Posted by bulgin

Hi All

I have a Dynaco SCA-35 which is still bog standard other than a thorough cleaning when I bought it, a repaired balance control, a new power lead, all original tubes etc. I have resisted any further mods (other than replacing the on/off switch and changing the amber lens for blue) for now as it still sounds so good (I know, I know)...

I have a couple of quiet fans here doing nothing. Do you think if I rig one of the fans to extract hot air from around the hot running components, I will prolong the amp's tubes and current performance? Will this arrangement do any harm?

Cheers

bulgin

My thoughts.
Too much dust/dirt and noise!
DT
All Just for fun!

[ArtG]

I feel that it's always a good idea to try to keep electronic circuits running cool and the obvious way is to use a fan. You didn't mention any particular mounting of your fans, but I think using them to exhaust heat through the top of the unit would be an easy and effective approach. Extra cooling is known to prolong the life of electrical components, but I highly doubt that you would hear any immediate improvement in sound quality.
One caution: low voltage DC fans can produce considerable electrical noise, so don't consider wiring them into the SCA-35 heater supply. Wall-warts are often used to power this sort of fan, but many wall-warts also produce electrical hash, so connect them into a separate line circuit if possible.

[bulgin]

Hello Guys

Thanks for the advice. No, I will not draw current for the fan from the heater supply. I will probably run the fan from rechargeables and mounting the fan in an inverted "L" frame attached with the cover's side screws as the fans I have weigh next to nothing.

I have no hopes for improved sound. My only concern is to prolong the life of the components.

I'll post a pic when done.

Regards

bulgin

[kruesi]

Keeping the components cooler is definitely a good idea. Using a fan is the obvious way to do this, but there are drawbacks:

* If the amp is in the same listening space as you, the acoustic noise from the fan may be a concern. After all that work to produce an amp with excellent hum & noise performance, it would ba a shame to have the acoustic noise from the fan be the thing that dominates the noise floor.

* Moving air means moving dust and dirt along with it- this can accumulate inside the amp- or in a filter, but then you'll need to periodically clean the filter.


Using a large diameter, slow moving fan may be the best way to keep things quiet (Rotron "whisper" with a dropping resistor) -and it's always a fine idea to contain and absorb the fan's acoustic noise to the extent possible.

All that being said, a fan will greatly extend the life of the amp- your power resistors, electrolytic capacitors and tubes will thank you.