Twincam Posted February 20, 2016 Share Posted February 20, 2016 My TE combo has an annoyingly loud fan and it constantly blows cold air on me when I'm practicing. So I want to fit a simple off/on switch to the fan. Just for low volume practicing in the house typically gain is at no more than 7 and the master volume is never past 2 in fact 1.5 is pretty loud and audible outside the house. Now before I do this I thought I best ask for advice on doing so. What's going to be the best method? And of course on a 7215 smc is it safe to do it at that volume? Quote Link to comment Share on other sites More sharing options...
discreet Posted February 20, 2016 Share Posted February 20, 2016 Just my 2p, but I wouldn't fit a switch... it would drastically increase the possibility of your amp being in a thermal stress situation, which I assume would lead to shutdown. Which could be embarrassing at a gig. For example... Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted February 20, 2016 Share Posted February 20, 2016 I'd fit a thermal switch on the heatsink near the output transistors and wire the fan in series with it. This, or fit a quieter fan with the same flow rate. Sit somewhere else or wear a jumper if the breeze upsets you. Quote Link to comment Share on other sites More sharing options...
Twincam Posted February 21, 2016 Author Share Posted February 21, 2016 [quote name='discreet' timestamp='1455974513' post='2984119'] Just my 2p, but I wouldn't fit a switch... it would drastically increase the possibility of your amp being in a thermal stress situation, which I assume would lead to shutdown. Which could be embarrassing at a gig. For example... [/quote] Well for these situations I know I would have to remember to switch the fan on again. [quote name='MoonBassAlpha' timestamp='1455976484' post='2984149'] I'd fit a thermal switch on the heatsink near the output transistors and wire the fan in series with it. This, or fit a quieter fan with the same flow rate. Sit somewhere else or wear a jumper if the breeze upsets you. [/quote] This could be a good idea. Quote Link to comment Share on other sites More sharing options...
4stringslow Posted February 21, 2016 Share Posted February 21, 2016 Buy a smaller combo without a fan for home practice? Quote Link to comment Share on other sites More sharing options...
discreet Posted February 21, 2016 Share Posted February 21, 2016 [quote name='Twincam' timestamp='1456015399' post='2984602'] Well for these situations I know I would have to remember to switch the fan on again. [/quote] That's the thing, isn't it? I wouldn't trust myself to remember. You're neurons may be in better condition than mine. Quote Link to comment Share on other sites More sharing options...
KingBollock Posted February 21, 2016 Share Posted February 21, 2016 I have considered doing this myself. The fans used are usually the same as those used in PCs. I have an old hard drive bay that has a thermostat and a couple of fans in it that I think would be ideal for this kind of thing. I would just use the thermostat, it should run on just the DC supplied to the fans in the amp. It only cost me about £7, donkey's years ago, and I have no use for it, so I don't mind cannibalising it. I would have it so that it could be switched in and out, so that it could be used just in the house but would be there to kick in if it was needed. I would imagine that you can still get them, I know you can get rather more complicated PC fan controllers. I'm sure there must be something cheap that could be used. Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted February 23, 2016 Share Posted February 23, 2016 (edited) Find out the spec of the fan, voltage and airflow. It is usually printed on the fan. Then find a new fan to relaxed the one you have. If you can get a Panaflo fan NOS use that otherwise a Papst or some of the better Sunon fans would be OK. One other technique is to use an overrated fan. Cloud do this in their PA amps. Running a 24 volt fan on 12v will mean it runs slower and quieter and lasts a Lot longer. One thing to beware of. Do not go above the maximum voltage as fans are easy to burn out if you do. Edited February 23, 2016 by Chienmortbb Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted February 23, 2016 Share Posted February 23, 2016 (edited) Hmm, I've got 4 80mm 24V fans on my desk going spare. They are very quiet at 12V... These ones: http://uk.rs-online.com/web/p/axial-fans/5415261/?searchTerm=541-5261&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6265724D504E266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B337D5B5C732D2F255C2E2C5D5C647B332C347D2426706F3D313426736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D3534312D3532363126 Edited February 24, 2016 by MoonBassAlpha Quote Link to comment Share on other sites More sharing options...
iiipopes Posted February 23, 2016 Share Posted February 23, 2016 I highly recommend not to. If you forget to turn it back on under load, you can cook the amp. I'm with the above - possibly a thermal switch? But you need to know the nominal acceptable operating temperature for it to come on, which the manufacturer may or may not want to disclose. Quote Link to comment Share on other sites More sharing options...
icastle Posted February 29, 2016 Share Posted February 29, 2016 I very much doubt you're going to find any detail on the optimal temperature range to rig up something for a thermal switch - and even if you could, you're still going to have to find a way of controlling the fan (circuitry) as thermal switching in an amp isn't crude like a central heating thermostat. You also have to get it in the right place, which is likely to present some engineering issues as no provision was ever made for it. Fan technology has moved on since the halcyon days of TE. I'd be way more inclined to just replace the fan for one of the same size, voltage and airflow and leave the circuit design alone - the original design has stood the test of time, why risk burning out the power transistors now... As for the cold breeze... Quote Link to comment Share on other sites More sharing options...
Grangur Posted March 1, 2016 Share Posted March 1, 2016 (edited) Fwiw I recon you have some good advice here. I only use my rig at home. So it's a constant situation for me. I'd suggest you either change the fan for a quieter one, or change the amp. It's also worth thinking about it the amp is under any guarantee. Changing anything will end the guarantee, even if you fit a better fan. It might also make the amp harder to sell. Edited March 1, 2016 by Grangur Quote Link to comment Share on other sites More sharing options...
icastle Posted March 1, 2016 Share Posted March 1, 2016 [quote name='Grangur' timestamp='1456820880' post='2992446'] Changing anything will end the guarantee, even if you fit a better fan. It might also make the amp harder to sell. [/quote] Would it be deeply immoral to suggest that keeping the original fan and popping it back in if there's a problem might be something worth considering..? Quote Link to comment Share on other sites More sharing options...
Twincam Posted March 1, 2016 Author Share Posted March 1, 2016 [quote name='icastle' timestamp='1456823627' post='2992483'] Would it be deeply immoral to suggest that keeping the original fan and popping it back in if there's a problem might be something worth considering..? [/quote] I don't think on an ancient Trace Elliot combo anything would be immoral haha. Anyhow just keeping it as is. The breeze will be nice in the summer, amazing how much air it pumps out though. A simple solution would be to fit tape across the front not blocking the air vents just redirecting the flow. Quote Link to comment Share on other sites More sharing options...
icastle Posted March 1, 2016 Share Posted March 1, 2016 [quote name='Twincam' timestamp='1456825811' post='2992515'] A simple solution would be to fit tape across the front not blocking the air vents just redirecting the flow. [/quote] Simpler still, don't sit in front of it... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.