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Old 10th November 2013, 08:33 AM   #921
rab28 is offline rab28  Australia
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Quote:
Originally Posted by rab28 View Post
However, the motivation for this post is that, when no music is playing, i can now hear a low level oscillation/feedback type whine that appears occasionally
Hi all, just a quick update to say that i have determined that the 'oscillation' noise in my Tram2 is the (Coleman regulator) cooling fans kicking in.

At this stage I am not sure whether its caused by EM radiation from the fan supply wires, or from the fans themselves, or noise injected back down to the supply from the fan motors (maybe the most likely?). I suppose the easiest first step is to try to shield the supply wires and see if that makes any difference.

Incidentally, my friend's Tram2 that does not have this problem has (cooling) holes drilled through the top of the chassis in addition to the fans: I wonder if the holes might be enough to stop the fan from coming on?

I note that my fans only stay on for something like 20-30 seconds... I suppose a possible work around might be to test the actual temperature of the regs at equilibrium and see if can avoid the fans kicking in at all during normal operation!

- richard
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Old 10th November 2013, 08:46 AM   #922
Desmo is offline Desmo  Denmark
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I would guess, that it's mechanical vibration from the fans. Try to have the fans running without mechanical contact, if that solves the problem you need better mechanical / vibration isolation in the way you mount them.
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Old 10th November 2013, 09:03 AM   #923
rab28 is offline rab28  Australia
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Thanks Morten, i bet you are correct: the character of the noise does seem consistent with vibration of the tube components!

Also, i had never noticed the noise until I started using an EML rectifier tube, so maybe it's vibration of only that rectifier tube that's causing the noise...!

- richard
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Old 10th November 2013, 10:18 AM   #924
kazap is offline kazap  England
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I used a fan under my Tram2 in the heat of last summer with early stock regulators. But the fan was powered on all the time, was powered with a linear 5v low noise supply plugged into a different outlet form the preamp, was a very low noise 12V design, had special bearings and was mounted via silicon to isolate direct vibration. It was noise free via the speakers and from 40cm away.

I think the airflow from drilling extra holes to get cooling via passive convection could be optimised using a chimney effect. The top transformer cover gets warm enough to likely augment updraught by attaching copper tubes with thermal paste around the back of the transformer cover.
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Old 10th November 2013, 10:19 AM   #925
работник
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Bob Magaletta [Magz] has done some work on quiet fans - maybe will help:

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Old 10th November 2013, 05:31 PM   #926
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Coming very late to this thread but hope someone here can help ....I've picked up a Tram2 (already built) ...

However it has no remote and I have no idea what remote I should buy to work with it.

Any suggestions on a simple remote to operate it? (ideal would be just with input selection and volume control but any remote at all really would be great).

If anyone has a pointer to something in particular (say on Amazon or eBay) that would be ideal.

I'm actually pretty short of remotes in here, I don't have a TV or DVD player any more (haven't had for years) so the only remote in operation is the one for the CD transport.
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Old 10th November 2013, 06:10 PM   #927
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I use a Maranz RC 1400
it is a universal remote...when i use the tape selection it works on the volume--
here is a link to the manual---on the last pages there is something about the remote

http://www.diyhifisupply.com/files/Tram2R1.36.pdf
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Old 11th November 2013, 09:46 AM   #928
rab28 is offline rab28  Australia
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Quote:
Originally Posted by Rod Coleman View Post
Bob Magaletta [Magz] has done some work on quiet fans - maybe will help:
Thanks Rod: i'll check it out!

Quote:
Originally Posted by montesquieu61 View Post
However it has no remote and I have no idea what remote I should buy to work with it.
Easy, as noted above, any universal remote should work (i use a Logitech Harmony 1). For codes, also see this thread: TRAM2 Remote Code for Logitech Harmony [EDIT: ah, i just noticed you already posted on that thread...]

Finally, diyaudiosupply probably still have the $20 remotes that they supply with the Tram. You could try contacting Simon. I seem to recall you can also buy them on eBay, but it would be easier to buy one from Simon, pre-programmed.

- r.
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Old 25th November 2013, 11:00 PM   #929
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Well.....Finally I have my very own Tram. At the moment it is a 2 box affair with separate transformers for the B+ and heaters etc. Thankfully I have no hum (my biggest worry). I was picking up some mechanical noise from the fans however I have now devised a way to keep them isolated.

I have, with the help of the generous posts of members in this forum implemented the following:

TJ 2A3 SE output tubes (thanks Morten )
Chatham 5998 Mu (others on order)
Emission Labs 5U4G

Coleman regs with Mortens upgrades (thanks Morten )
Duelund CAST input caps (thanks Morten )
Obligato 2.2 X6 output caps (thanks Morten )
SHINKOH Resistors throughout (thanks Morten )

I could feel my heart in my throat and my stomach turning on first connected turn on and initially the left channel was out........ I traced it down to a faulty resistor in shunt mode. All fixed and sounding wonderful. Now for the burn in.

Thank you again

Greg
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Old 17th December 2013, 07:57 PM   #930
Falck is offline Falck  Sweden
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Default Headphones - Tram mk2 question

Pardon my limited knowledge, but is it possible to use Headphones, Sennheiser HD 650 (impedance 300 ohm), directly from the Tram mk2 output? If not, does anyone have a suggestion of a modification, external converter etc. Do I need a separate headphone amp?
Regards, Mats Falck
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