Tek 2215 question

D

Don Lancaster

Guest
Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.

I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Still could not get the noise acceptably low.

This is apparently a chronic problem that infects a significant number
of 2215's and probably 2213's as well.

Any cures or workarounds out there?

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: don@tinaja.com

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
AFAIK, there are no easy workarounds. As you probably are aware, Tek
came out with a retrofit kit that replaced the nasty triac prereg with
a TL594 based MOSFET prereg like in the later 2215A series. Actually,
the TL594 prereg is not that complex; I thought about building up a
small kit myself; but I would have to come up with one part that would
not be easy; the buck transformer. I have a couple of dead 2235's
around here; maybe someday I'll unwind one of those to see about
replicating them.

Jeff

On Mon, 16 Feb 2004 20:58:33 -0700, Don Lancaster <don@tinaja.com>
wrote:

Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.

I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Still could not get the noise acceptably low.

This is apparently a chronic problem that infects a significant number
of 2215's and probably 2213's as well.

Any cures or workarounds out there?
Click to expand...
 
Jim Yanik <jyanik@abuse.gov> writes:

Jeff W <vwthingy@NOSPAMcox.net> wrote in
news:8mb330t0k0eu82fsbtm1rd6dd06kmvs8ld@4ax.com:

AFAIK, there are no easy workarounds. As you probably are aware, Tek
came out with a retrofit kit that replaced the nasty triac prereg with
a TL594 based MOSFET prereg like in the later 2215A series. Actually,
the TL594 prereg is not that complex; I thought about building up a
small kit myself; but I would have to come up with one part that would
not be easy; the buck transformer. I have a couple of dead 2235's
around here; maybe someday I'll unwind one of those to see about
replicating them.

Jeff

On Mon, 16 Feb 2004 20:58:33 -0700, Don Lancaster <don@tinaja.com
wrote:


Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.

I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Still could not get the noise acceptably low.

This is apparently a chronic problem that infects a significant number
of 2215's and probably 2213's as well.

Any cures or workarounds out there?



Or you could create a ordinary (60Hz)transformer based 43 volt DC supply to
replace the pre-reg.It would have to supply at least 1 amp at 43V,and would
only work for whatever primary voltage you selected for the XFMR,not the
90-250 VAC range of the Opt.48 pre-reg.
Click to expand...
Or maybe just a commercial AC-DC 48 V brick adjusted down to 43 V or
dropped to 43 V.

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Important: The email address in this message header may no longer work. To
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I read in sci.electronics.design that Jim Yanik <jyanik@abuse.gov> wrote
(in <Xns94926AF453279jyanikkuanet@204.117.192.21>) about 'Tek 2215
question', on Tue, 17 Feb 2004:

Or you could create a ordinary (60Hz)transformer based 43 volt DC supply
to replace the pre-reg.It would have to supply at least 1 amp at 43V,and
would only work for whatever primary voltage you selected for the
XFMR,not the 90-250 VAC range of the Opt.48 pre-reg.
Click to expand...
I have a small audio weighting filter, made by Dolby Laboratories, which
has a *linear* power supply covering 80 to 250 V without adjustment. It
has two small lamps in series with the transformer primary winding. But
that would be one crazy panel light if you did it with a 43 W output
linear supply!
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
Don Lancaster <don@tinaja.com> wrote in news:40319169.C6DB1427@tinaja.com:

Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.

I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Still could not get the noise acceptably low.

This is apparently a chronic problem that infects a significant number
of 2215's and probably 2213's as well.

Any cures or workarounds out there?
Click to expand...
Welll,the original TEK cure(mod) was to clip out the original Triac pre-reg
circuitry and install a separate pre-reg PCB based on a TL494 IC.(also
referred to as OPT.48) I have one of these in my 2213.

TEK also tried a rubber cushion,but it didn't work.

Maybe installing a different inductor would work.

--
Jim Yanik
jyanik-at-kua.net
 
Jeff W <vwthingy@NOSPAMcox.net> wrote in
news:8mb330t0k0eu82fsbtm1rd6dd06kmvs8ld@4ax.com:

AFAIK, there are no easy workarounds. As you probably are aware, Tek
came out with a retrofit kit that replaced the nasty triac prereg with
a TL594 based MOSFET prereg like in the later 2215A series. Actually,
the TL594 prereg is not that complex; I thought about building up a
small kit myself; but I would have to come up with one part that would
not be easy; the buck transformer. I have a couple of dead 2235's
around here; maybe someday I'll unwind one of those to see about
replicating them.

Jeff

On Mon, 16 Feb 2004 20:58:33 -0700, Don Lancaster <don@tinaja.com
wrote:


Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.

I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Still could not get the noise acceptably low.

This is apparently a chronic problem that infects a significant number
of 2215's and probably 2213's as well.

Any cures or workarounds out there?
Click to expand...
Or you could create a ordinary (60Hz)transformer based 43 volt DC supply to
replace the pre-reg.It would have to supply at least 1 amp at 43V,and would
only work for whatever primary voltage you selected for the XFMR,not the
90-250 VAC range of the Opt.48 pre-reg.

--
Jim Yanik
jyanik-at-kua.net
 
On a sunny day (Tue, 17 Feb 2004 15:28:22 +0000 (UTC)) it happened Jim Yanik
<jyanik@abuse.gov> wrote in <Xns94926AF453279jyanikkuanet@204.117.192.21>:
Or you could create a ordinary (60Hz)transformer based 43 volt DC supply to
replace the pre-reg.It would have to supply at least 1 amp at 43V,and would
only work for whatever primary voltage you selected for the XFMR,not the
90-250 VAC range of the Opt.48 pre-reg.
Its magnetic field might perhaps screw up the display.
Click to expand...
Plastic spray worked on line output transformers in TV, not sure it is of
use here.
 
Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.
I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.
Click to expand...
Have you considered active noise mitigation - bolt a voice coil to it
and inject a 180-degree-out-of-phase signal to damp the vibration? :)
 
"Lewin A.R.W. Edwards" wrote:
Every once in a while one of these comes up with a back panel singing
inductor that up-the-wall whines.
I tried everything reasonable involving damping the tuning fork like
shield, rubber mounts, etc.

Have you considered active noise mitigation - bolt a voice coil to it
and inject a 180-degree-out-of-phase signal to damp the vibration? :)
Click to expand...
It makes more sense to sell the unit to a deaf person.

--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: don@tinaja.com

Please visit my GURU's LAIR web site at http://www.tinaja.com
 
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