# Traynor YBA3 custom special...removing the fan?



## bolero (Oct 11, 2006)

hey I have a great sounding YBA3 loaded with 6550 power tubes

problem is: during recording the fan noise is getting picked up, very annoying

do these amps really need a fan?

alternately, is there a better/quieter fan I can replace it with? not sure what the voltage etc is on the stock unit, but a high end computer fan with ball bearings might do the trick?

thx


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## greco (Jul 15, 2007)

From this schematic, it would appear that the fan is connected to the AC mains supply before the power transformer. It appears to have a 100ohm /10 watt power resistor connected in series with it.

http://www.lynx.net/~jc/670113_Yba3.gif

Left click on the above linked .gif to enlarge it and look at the top, left corner.

I am NOT an amp tech...just trying to help. 

Cheers

Dave


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## greco (Jul 15, 2007)

I have been thinking about this problem you are having.

You might want to consider talking to an amp tech about putting a toggle switch in the fan circuit.
This would enable you to turn the fan off during recording and keep it on while not recording.

Seems like a simple, inexpensive solution.

Cheers

Dave


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## nonreverb (Sep 19, 2006)

For what it's worth, I've worked on some of these with the fan either long gone or in pieces. They worked just fine...
If you feel a fan is necessary, you can always make a little AC to DC supply and run a 12DC fan off that. It'll be very quiet.


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## traynor_garnet (Feb 22, 2006)

Why not simply buy a longer speaker cable and set the head further away from the cab and mic? Your mic isn't going to pick up that fan from any distance, especially if you are playing above whisper levels (which I assume you are given your choice of rig).

TG


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## greco (Jul 15, 2007)

@nonreverb...I have always wondered if AC fans tend to be noisy because they are AC, and therefore cause some sort of "electrical" noise, or because they move a large volume of air....or both?

Thanks

Cheers

Dave


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## nonreverb (Sep 19, 2006)

Like a transformer, induction fans generate some alternating magnetic fields around them. You shouldn't have too much problem though with them inducing hum on signal lines if that's what you mean by "electrical". I know they certainly can cause problems with Hammond organs as their matching transformers are 5000/1 turns ratio and are located close to the top edge of the cabinet in certain models.
I think most if not all the noise is due to old dirty armatures, bearings or bushings and the inherent hum they emit themselves.



greco said:


> @nonreverb...I have always wondered if AC fans tend to be noisy because they are AC, and therefore cause some sort of "electrical" noise, or because they move a large volume of air....or both?
> 
> Thanks
> 
> ...


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## bolero (Oct 11, 2006)

traynor_garnet said:


> Why not simply buy a longer speaker cable and set the head further away from the cab and mic? Your mic isn't going to pick up that fan from any distance, especially if you are playing above whisper levels (which I assume you are given your choice of rig).
> 
> TG


hey not a bad idea, I can even just put the head BEHIND the 8x10 cab, that might block

I believe some of the noise is coming thru the speakers too though, due to mech vibration it shakes the head pretty good


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## nonreverb (Sep 19, 2006)

That would suggest that the fan's rotation is very eccentric and that the tubes are really loose and are rattling. If that's the case, I'd check the tubes first. 
Fan or no fan, amp heads and especially combo amps get vibrated every time you play.
If, on the off chance the fan is inducing noise in the circuit, disconnect it or have the amp looked at to see where the noise is being induced.



bolero said:


> hey not a bad idea, I can even just put the head BEHIND the 8x10 cab, that might block
> 
> I believe some of the noise is coming thru the speakers too though, due to mech vibration it shakes the head pretty good


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## TheRumRunner (Sep 29, 2011)

Bolero, I had the same problem with my YBA-1A. As others have noted above, I installed a toggle to shut the fan off when needed.

In addition, much to my love for all things original. I replaced the fan that had seen more bars than 10 bar flies in 10 lifetimes. I did however scrape off the mojo dust for future useage - you can never have too much mojo dust.


















Replaced with...


















DW


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## bolero (Oct 11, 2006)

ha, that looks remarkably similar to the gunk on my fan before I cleaned it up 

I think I'll do that mod, makes a lot of sense

thanks!


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## Wild Bill (May 3, 2006)

Chris, tubes LOVE air flow! It dramatically increases tube life. Your amp will work fine without a fan but your 6550's won't last as long.

All the YBA-3s I ever worked on had a brand of fan that had a little removable cap in the centre that can be pried up. A drop or two of light sewing machine oil placed inside usually quiets them down. 

The bearings seem to hold up but the excess noise comes from lubrication having dried up over the years.

The suggestion to use a 12 volt DC computer power supply fan is a good one. Usually you can use the 6 vac filament supply and rectify it. Put a 2200 mfd 16 vdc or more filter cap on it and it will be smooth enough for a motor. With 6 volts and the motor loading the cap you will likely get about 8 vdc for the fan. This will mean the 12 volt fan will run slower - and thus quieter. You don't need a hurricane of air flow. As long as the air is constantly being pushed out of the cab and not being trapped as in an oven to get hotter and hotter it will be enough for the tubes.

Wild Bill


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