I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe

Joe wrote:
I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe


Try finding an old Heathkit supply. I picked up an IP-32 for a few bucks
that does exactly what you need, 0-400v with filament and even a
negative 0-150 bias supply. That or hang around your university. Mine
tossed some old rackmount Lamda supplies that work fine.

Or you could always get a small variac and 120-240 step up transformer
with a diode bridge. Make sure whatever you use is isolated from the
line. I used a setup like that before getting a real supply.


Adam

I have an old tube power supply, bench type. It's a beauty, supplying lots
of 6.3 V and up to 500V DC and variable bias, I think the main output is
good to a few hundred milliamperes. Two big meters. On a rack panel, heavy
as the dickens.

I don't use this thing and would like someone to make me an offer.

I also have a smaller one on a little chassis that isn't variable or
regulated. That I would sell cheaper, or even trade for something.

Bob in Los Angeles

On Fri, 05 Nov 2004 00:15:41 +0000, Joe wrote:


I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for experimenting
with some pre-amp designs, but I'm having trouble finding something
suitable.

Based on the reading I've done, I was thinking the PS should be variable
from about 150VDC to 400VDC @100mA for the plates, and fixed at about 6VAC
@ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like this.

Does anyone know of any bench supplies, or kits, or schematics like this -
or have other suggestions?


I've used a Radford N15R power pack for preamp stages & similar low
current stuff. Quite a few of these have been disposed of by schools over
the years - they were originally used for the physics course before people
decided that things like x-ray tubes were too dangerous for us kids!

Get a smalli variac and use it to drive the primary of a reasonable mains
tranny for the HT. Ignore the heater windings on this. This should be
independently switched. SS rectifier & suitable caps rated for the full
output (fit bleeder resistors and a voltmeter). Use second and possible
third heater trannys, not fed via the variac. Also a seperate bias supply
using a ww pot and giving up to say 100v should be ok for a lot of stuff.

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info

And here's another one for you.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=3849963 251





"mick" wrote in message
news
On Fri, 05 Nov 2004 00:15:41 +0000, Joe wrote:


I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for experimenting
with some pre-amp designs, but I'm having trouble finding something
suitable.

Based on the reading I've done, I was thinking the PS should be variable
from about 150VDC to 400VDC @100mA for the plates, and fixed at about
6VAC
@ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this -
or have other suggestions?


I've used a Radford N15R power pack for preamp stages & similar low
current stuff. Quite a few of these have been disposed of by schools over
the years - they were originally used for the physics course before people
decided that things like x-ray tubes were too dangerous for us kids!

Get a smalli variac and use it to drive the primary of a reasonable mains
tranny for the HT. Ignore the heater windings on this. This should be
independently switched. SS rectifier & suitable caps rated for the full
output (fit bleeder resistors and a voltmeter). Use second and possible
third heater trannys, not fed via the variac. Also a seperate bias supply
using a ww pot and giving up to say 100v should be ok for a lot of stuff.

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info

I was looking at this one already
Looks great
wish I could afford to buy new stuff right now
but oh well I have a good bench supply that is almost exactly like the
Heathkit.
0-450V at 150ma and 0-150V 2ma and a pair of 6.3V 3A supplies
does the job for now
but I would love to have that 600V supply

Doug


wrote in message
. ..
And here's another one for you.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=3849963 251





"mick" wrote in message
news
On Fri, 05 Nov 2004 00:15:41 +0000, Joe wrote:


I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting
with some pre-amp designs, but I'm having trouble finding something
suitable.

Based on the reading I've done, I was thinking the PS should be
variable
from about 150VDC to 400VDC @100mA for the plates, and fixed at about
6VAC
@ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this -
or have other suggestions?


I've used a Radford N15R power pack for preamp stages & similar low
current stuff. Quite a few of these have been disposed of by schools over
the years - they were originally used for the physics course before
people
decided that things like x-ray tubes were too dangerous for us kids!

Get a smalli variac and use it to drive the primary of a reasonable mains
tranny for the HT. Ignore the heater windings on this. This should be
independently switched. SS rectifier & suitable caps rated for the full
output (fit bleeder resistors and a voltmeter). Use second and possible
third heater trannys, not fed via the variac. Also a seperate bias supply
using a ww pot and giving up to say 100v should be ok for a lot of stuff.

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info

Joe,

I have an extra Heathkit power supply that I would sell for a reasonable
price. Please reply to the group if you are interested. BTW, I tried to
reply to the post but my email was bounced back.

Regards,

Mark


"Joe" wrote in message
...

I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe

Thanks a lot for all the great suggestions. I really like the idea of
using a variac to control the mains - hadn't thought of doing that.

I ended up buying a Heathkit IP-17 from a buddy of mine at work. It's
in great shape and has outputs similar to the IP-32.

He told me that the regulation was good, but not superior - which I
think is fine for what I'm doing.

I did find an interesting web page where these fellows had modified an
IP-17 to create a microprocessor controlled HV supply.

http://www.tech-diy.com/MCTracer_no_...webversion.htm


Not quite what I'm looking to do, but interesting nonetheless.





On Fri, 05 Nov 2004 00:15:41 GMT, Joe wrote:


I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe

Joe wrote:
Thanks a lot for all the great suggestions. I really like the idea
of
using a variac to control the mains - hadn't thought of doing that.

That takes a seperate tranny for the fillaments, and they can go a lot
higher than 2A. A pair of EL34's or 6550's will draw 3A. I'm building
one with seperate supplies for 5V @ 4A and 6.3V @ 8A. The Variac will
be hooked up to a 5:1 step-up transformer for forming 'lytics. I'm
still looking for a regulator circuit, though. I've seen one by Dan
Torres that used a 6BM8 tube, but I've lost the scematic.

Yes, I was thinking two variacs and two transformers (one set each for
plate and bias supplies) might be a good idea. Then perhaps another
transformer for the 5V & 6V supplies.

I found a set of website that discusses tube-based regulation and
error control circuits - including schematics and test results.

http://members.aol.com/sbench/reg1.html

It was well researched and presented, I thought.


On 7 Nov 2004 10:58:42 -0800, "kseely" wrote:


Joe wrote:
Thanks a lot for all the great suggestions. I really like the idea
of
using a variac to control the mains - hadn't thought of doing that.

That takes a seperate tranny for the fillaments, and they can go a lot
higher than 2A. A pair of EL34's or 6550's will draw 3A. I'm building
one with seperate supplies for 5V @ 4A and 6.3V @ 8A. The Variac will
be hooked up to a 5:1 step-up transformer for forming 'lytics. I'm
still looking for a regulator circuit, though. I've seen one by Dan
Torres that used a 6BM8 tube, but I've lost the scematic.

Look around for a Fluke 407 or 407D. Best looking piece of gear I ever
owned - big knobs, huge meter. 6.3vAC filaments @ 10A, B+ adjust to
550VDC @300mA, bias adj to -250V. B+ & bias are well regulated. fils are
sort of regulated w/ ballast tube. Mine has been working non stop for
10 years and it was probably 30 years old when I got it though I did
re-cap it.
Todd

Joe wrote:
I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe

Yes,
IP-17 is the way to go!
ebay can make them very affordable if you have time to buy.

Giles

On Sun, 07 Nov 2004 17:07:56 GMT, Joe wrotf:


Thanks a lot for all the great suggestions. I really like the idea of
using a variac to control the mains - hadn't thought of doing that.

I ended up buying a Heathkit IP-17 from a buddy of mine at work. It's
in great shape and has outputs similar to the IP-32.

He told me that the regulation was good, but not superior - which I
think is fine for what I'm doing.

I did find an interesting web page where these fellows had modified an
IP-17 to create a microprocessor controlled HV supply.

http://www.tech-diy.com/MCTracer_no_...webversion.htm


Not quite what I'm looking to do, but interesting nonetheless.





On Fri, 05 Nov 2004 00:15:41 GMT, Joe wrote:


I'm an electronics student interested in learning about tube amplifier
circuits. I'm looking for a bench power supply to use for
experimenting with some pre-amp designs, but I'm having trouble
finding something suitable.

Based on the reading I've done, I was thinking the PS should be
variable from about 150VDC to 400VDC @100mA for the plates, and fixed
at about 6VAC @ 2A and 5VDC @ 2A for the heaters.

Maybe I'm way off base here, but I can't seem to find anything like
this.

Does anyone know of any bench supplies, or kits, or schematics like
this - or have other suggestions?

Thanks!
Joe