in article , Ian Thompson-Bell at
wrote on 12/23/07 4:12 PM:

Jon Yaeger wrote:
in article , Ian Thompson-Bell at
wrote on 12/23/07 8:28 AM:

I am building a tube based mic pre into a 19inch rack case which is
painted black. I want to label the inputs, outputs and controls. What
options are open to a hobbyist?

Cheers

Ian


DATAK bran transfer letters are probably the most available and easy-to-use
solution.

Is this the same as Letraset or different in some fundamental way?

Cheers

Ian


Ian,

I dunno because I haven't seen or tried the Letraset . . .

In article ,
Raymond Koonce wrote:

John Byrns wrote:
In article ,
Raymond Koonce wrote:

Hi John,

Not entirely my idea. A friend built an amp using this tube and liked
it. I had several pairs and some appropriate transformers, so I decided
to build something with what I had. About the only thing I didn't have
on hand was the copper chassis. All in all it's a nice amp, but I still
have some issues with the 816s to resolve. I would like to have a small
(2uF or so) cap on the input to the PS, but the 816s don't like it.

I don't follow you, why would you like a 2 uF capacitor on the input to
the PS, is the B+ too low?

Yes, I'd like the B+ just a little higher and it's easy to do with a
small cap if you're using a vacuum rectifier. The amp is pretty nice as
is though.

What B+ do you have now and what do you want? Here is a crazy idea that
might or might not work, it's tempting me to fire up my old computer
that has Spice on it and see what happens with a simolation.

Idea, add an input capacitor considerably larger than 2 uF and then add
enough additional impedance between the rectifiers and the added
capacitor to keep the repetitive peak current to 500 mA as per the 816
spec. The added impedance could be an input inductor of smaller than
normal value, but large enough to control the repetitive peak currents,
or there is a chance even a resistor might work as the added impedance,
depending on the currents involved, although it would get fairy warm.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

"Raymond Koonce" wrote in message
...
John Byrns wrote:
In article ,
Raymond Koonce wrote:

Hi John,

Not entirely my idea. A friend built an amp using this tube and liked
it. I had several pairs and some appropriate transformers, so I decided
to build something with what I had. About the only thing I didn't have
on hand was the copper chassis. All in all it's a nice amp, but I still
have some issues with the 816s to resolve. I would like to have a small
(2uF or so) cap on the input to the PS, but the 816s don't like it.

I don't follow you, why would you like a 2 uF capacitor on the input to
the PS, is the B+ too low?


Regards,

John Byrns

Yes, I'd like the B+ just a little higher and it's easy to do with a small
cap if you're using a vacuum rectifier. The amp is pretty nice as is
though.


Why not use a different rectifier?. The current consumption of your amp will
be quite modest so many of the ordinary vacuum rectifiers of the period
should work just fine.

David.

John Byrns wrote:
In article ,
Raymond Koonce wrote:

John Byrns wrote:
In article ,
Raymond Koonce wrote:

Hi John,

Not entirely my idea. A friend built an amp using this tube and liked
it. I had several pairs and some appropriate transformers, so I decided
to build something with what I had. About the only thing I didn't have
on hand was the copper chassis. All in all it's a nice amp, but I still
have some issues with the 816s to resolve. I would like to have a small
(2uF or so) cap on the input to the PS, but the 816s don't like it.
I don't follow you, why would you like a 2 uF capacitor on the input to
the PS, is the B+ too low?

Yes, I'd like the B+ just a little higher and it's easy to do with a
small cap if you're using a vacuum rectifier. The amp is pretty nice as
is though.

What B+ do you have now and what do you want? Here is a crazy idea that
might or might not work, it's tempting me to fire up my old computer
that has Spice on it and see what happens with a simolation.

Idea, add an input capacitor considerably larger than 2 uF and then add
enough additional impedance between the rectifiers and the added
capacitor to keep the repetitive peak current to 500 mA as per the 816
spec. The added impedance could be an input inductor of smaller than
normal value, but large enough to control the repetitive peak currents,
or there is a chance even a resistor might work as the added impedance,
depending on the currents involved, although it would get fairy warm.


Regards,

John Byrns

My B+ is about 245, IIRC. (It's sort of hard to measure this amp
because I can't run it upside down because of the MV tubes.) I'd like
to get about 270 to 275. I'd appreciate some suggestions as to
component values. I hadn't considered this approach.

Also, I have some hash from the 816s, not much, but I'd like to get rid
of it. Do you have any suggestions there?

BR,

Raymond

"Raymond Koonce" wrote in message
...
John Byrns wrote:
In article ,
Raymond Koonce wrote:

John Byrns wrote:
In article ,
Raymond Koonce wrote:

Hi John,

Not entirely my idea. A friend built an amp using this tube and liked
it. I had several pairs and some appropriate transformers, so I
decided to build something with what I had. About the only thing I
didn't have on hand was the copper chassis. All in all it's a nice
amp, but I still have some issues with the 816s to resolve. I would
like to have a small (2uF or so) cap on the input to the PS, but the
816s don't like it.
I don't follow you, why would you like a 2 uF capacitor on the input to
the PS, is the B+ too low?

Yes, I'd like the B+ just a little higher and it's easy to do with a
small cap if you're using a vacuum rectifier. The amp is pretty nice as
is though.

What B+ do you have now and what do you want? Here is a crazy idea that
might or might not work, it's tempting me to fire up my old computer that
has Spice on it and see what happens with a simolation.

Idea, add an input capacitor considerably larger than 2 uF and then add
enough additional impedance between the rectifiers and the added
capacitor to keep the repetitive peak current to 500 mA as per the 816
spec. The added impedance could be an input inductor of smaller than
normal value, but large enough to control the repetitive peak currents,
or there is a chance even a resistor might work as the added impedance,
depending on the currents involved, although it would get fairy warm.


Regards,

John Byrns

My B+ is about 245, IIRC. (It's sort of hard to measure this amp because
I can't run it upside down because of the MV tubes.) I'd like to get
about 270 to 275. I'd appreciate some suggestions as to component values.
I hadn't considered this approach.

Also, I have some hash from the 816s, not much, but I'd like to get rid of
it. Do you have any suggestions there?

Yes, don't use MV rectifiers, to be honest I cannot see any reason to do so.
In your application they are seriously OTT anyway.

I just found this on the web:

quote
Don't use MV....they are one family of tubes that deserve to be forgotten.
unquote

A sentiment with which I wholeheartedly concur.

David.

"Ian Thompson-Bell" wrote in
message

3) If you like playing computer a lot you can print a
transfer on clear self adhesive stock to cover your
entire front panel, using a laser printer.

Or, you use an inkjet.

In either case you probably want to put a transparent layer over it by
several possible means.

This can look
great if everything is scaled correctly and you get the
transfer applied straight.

That sounds interesting - only problem is how do you make
hole for the post and switches?

You attach the adhesive stock to the pre-punched front panel, and then trim
the holes from the inside out with something sharp like an X-acto knife.

Or, if you are in a hurry, you make a cross-cut in the middle of the holes
and just push the pot or switch into the hole, using its threads to cut the
plastic stock to size.

"Ian Thompson-Bell" wrote in message
...
: Andre Jute wrote:
: Ian Thompson-Bell wrote:
:
: I am building a tube based mic pre into a 19inch rack case which is
: painted black. I want to label the inputs, outputs and controls. What
: options are open to a hobbyist?
:
: Cheers
:
: Ian
:
: Undoubtedly the most professional way to do it is to design the art in
: a page layout or other vector art programme on your computer and have
: it professionally silkscreened onto the metal.
:
: major snippage
:
: Many Thanks Andre, some really good ideas there. I have saved your email
: for future reference.
:
: Cheers
:
: Ian

...agreed, however, as a correction, it _is_ very well possible to get white
on transparancy
printing done, most of the larger copyshops usually have (Canon) machines
that have
multiple toners available, *including white* - check around :-)

Happy Holidays all,

Rudy

Here is an example of Datak lettering applied to a replacement front panel
for an Eico 2080 amplifier.

The panel was sprayed with a matte protective coating:

in article , Jon Yaeger at
wrote on 12/24/07 5:36 PM:

Here is an example of Datak lettering applied to a replacement front panel
for an Eico 2080 amplifier.

The panel was sprayed with a matte protective coating:

http://www.yaegeraudio.com/panel1.jpg


And here is the panel with approximate knob placement:

http://www.yaegeraudio.com/panel2.jpg

A little funky, I suppose, but it'll get 'er done.

Now off to cook Xmas dinner . . . .

Jon

Jon Yaeger wrote:
in article , Jon Yaeger at
wrote on 12/24/07 5:36 PM:

Here is an example of Datak lettering applied to a replacement front panel
for an Eico 2080 amplifier.

The panel was sprayed with a matte protective coating:

http://www.yaegeraudio.com/panel1.jpg


And here is the panel with approximate knob placement:

http://www.yaegeraudio.com/panel2.jpg

A little funky, I suppose, but it'll get 'er done.

Now off to cook Xmas dinner . . . .

Jon



Yup, and put the presents under the tree before the grandchildren get here.

Cheers

Ian