How would one approach retrofitting a remote control to a ready-made preamp?
Am I right in thinking that I could put some kind of receiver into the amp
and use an existing remote? I don't envisage a need to do anything other
than volume up/down and mute.

What's the cheapest way to get a receiver? Maplin seem to do a few kits /
modules - lots of them are 'two channel' - do I need three channels, hence
two receivers? What about making one on Veroboard? Are there standard
circuits which would make it little more than a soldering job, or is design
effort needed? The Maplin receivers that I have my eye on are 13 quid each
(H96AU) and have the learning thingy for channel codes, and they do a nice
little remote for a tenner (PW32K).

What about controlling the amplifier? The first thing I thought of was a
motor drive on the existing volume control, and a relay for the mute. I
don't know yet if I can control the volume pot from inside, but, if I can,
then the mechanical bits can be done, but at a cost in effort. I'm not sure
about the implications of driving a motor from the amp's PSU - I don't know
if it has enough power in reserve, or whether there might be noise problems.
I feel that, if I have to start building circuit boards to account for the
addition of a motor, then maybe it would be feasible to do it all
electronically. If it is, can it be done without degrading the sound
quality? What ways are there to approach it? My lack of knowledge of the
subject says to somehow alter the gain of an existing amplifier stage, on
the assumption that that would be outside the signal path - but I have no
idea if I'm right.


--
Wally
www.forthsailing.com
www.wally.myby.co.uk

"Wally" wrote:
in ,
on Sat, 8 May 2004 22:40:12 +0100,

: How would one approach retrofitting a remote control to a ready-made preamp?
: Am I right in thinking that I could put some kind of receiver into the amp
: and use an existing remote? I don't envisage a need to do anything other
: than volume up/down and mute.
:
: What's the cheapest way to get a receiver? Maplin seem to do a few kits /
: modules - lots of them are 'two channel' - do I need three channels, hence
: two receivers? What about making one on Veroboard? Are there standard
: circuits which would make it little more than a soldering job, or is design
: effort needed? The Maplin receivers that I have my eye on are 13 quid each
: (H96AU) and have the learning thingy for channel codes, and they do a nice
: little remote for a tenner (PW32K).
:
: What about controlling the amplifier? The first thing I thought of was a
: motor drive on the existing volume control, and a relay for the mute. I
: don't know yet if I can control the volume pot from inside, but, if I can,
: then the mechanical bits can be done, but at a cost in effort. I'm not sure
: about the implications of driving a motor from the amp's PSU - I don't know
: if it has enough power in reserve, or whether there might be noise problems.
: I feel that, if I have to start building circuit boards to account for the
: addition of a motor, then maybe it would be feasible to do it all
: electronically. If it is, can it be done without degrading the sound
: quality? What ways are there to approach it? My lack of knowledge of the
: subject says to somehow alter the gain of an existing amplifier stage, on
: the assumption that that would be outside the signal path - but I have no
: idea if I'm right.

Have a look at http://stiftsbogtrykkeriet.dk/~mcs/Remote/index.html
(and http://stiftsbogtrykkeriet.dk/~mcs/Remote3/index.html )

Mikkel Simonsen hangs out on rec.audio.tubes, and I'm sure could fix you up
with a PCB or complete kit for either of those, if you were interested.
The first one is perhaps all you want, or need, judging from your post.
Well worth supporting, IMO. I look forward to obtaining one myself sometime.
There's a relay attentuator version in the works as well, I believe.
[Courtesy email copy to Mikkel...]
Perhaps he might drop in to this thread and comment further himself.
Ross M.
(in .nz, not .zn! :-)

RdM wrote:

Have a look at http://stiftsbogtrykkeriet.dk/~mcs/Remote/index.html
(and http://stiftsbogtrykkeriet.dk/~mcs/Remote3/index.html )

Thanks for the pointer. I had considered input switching, but felt that
getting it to work might be too much hassle for something that I didn't feel
was hugely neccessary. Seeing that Mikkel seems to have this worked out,
then maybe it's worth going for after all.


Mikkel Simonsen hangs out on rec.audio.tubes, and I'm sure could fix
you up with a PCB or complete kit for either of those, if you were
interested.

The price for the board kit looks similar to the Maplin stuff (although I
suspect the motorised Alps volume control would be pricey). Given that it's
dedicated to the purpose, I guess this might be the better option.


The first one is perhaps all you want, or need, judging from your
post. Well worth supporting, IMO. I look forward to obtaining one
myself sometime.

If you make a start, post something here. I'm looking at a project for
sometime next winter - just researching the options at present.


There's a relay attentuator version in the works as
well, I believe.

Do you mean a mute funtion?


--
Wally
www.forthsailing.com
www.wally.myby.co.uk

"Wally" wrote:

: There's a relay attentuator version in the works as
: well, I believe.
:
: Do you mean a mute funtion?

No, a way of switching between resistors in an input attenuator in
combinations so that only two resistors are in circuit at any time, with only
a few relays ... have a look here for some discussion (and links) on it.
http://tinyurl.com/2zuxy

RdM wrote:

No, a way of switching between resistors in an input attenuator in
combinations so that only two resistors are in circuit at any time,
with only a few relays ... have a look here for some discussion (and
links) on it. http://tinyurl.com/2zuxy

Ah, I get the idea. Does that method sound 'steppy', or is the transition
smooth?


--
Wally
www.artbywally.com
www.wally.myby.co.uk

"Wally" wrote:

: RdM wrote:
:
: No, a way of switching between resistors in an input attenuator in
: combinations so that only two resistors are in circuit at any time,
: with only a few relays ... have a look here for some discussion (and
: links) on it. http://tinyurl.com/2zuxy
:
: Ah, I get the idea. Does that method sound 'steppy', or is the transition
: smooth?

I'm no expert, just keeping mental notes on discussions I see for when/if I
get around to making/buying parts for (probably Mikkels) such a remote -
controlled preamp, whether stepped relay attenuator or motorised pot.

However, if the steps are small enough each level should be a barely
discernable increase from the last, I guess. One can vary the ammount of
"granularity" for different parts of the curve if one wishes.

The last article/thread linked in the list shows a link to a curve with 39
steps from 8 relays and max attenuation 48 dB.

Why not email Mikkel from his website link and ask him how the relay prototype
is coming along, or for availablity of the remote controlled pot version?

Cheers,
RdM