Anyone familiar with this Lite remote volume kit?

[mcs]

You mentioned a 64 step attenuator - is this built with individual relays that select a resistor (or set of resistors), or are you driving a rotary switch, or is it a motorized pot (shouldn't be, or I don't understand how the steps work)?

The signal passes through different combinations of resistors, which create 64 different levels of attenuation.

I have a transformer attenuator that has multiple transformer taps connected to a (manual) rotary switch. I'm interested too if this is something that I can use. If the person buying it can swap in his own resistors into it, I think I should be able to make it work with my transformers.

You would need a different type of board with as many relays as you have taps on your transformer. How many is that BTW? 24? I'm thinking of making one like that as well. I have made one already, as you can see in the other attenuator thread, but I'm planning one with the relays on the board (for simpler wiring). The circuit would look a lot like the one I use on the 64-step attenuator, but with a 32-output relay driver instead of a 7-output type.

Best regards,

Mikkel C. Simonsen

 

[Saurav]

You would need a different type of board with as many relays as you have taps on your transformer.

That's what I thought. Mine has 18 taps, but I think if you built something with 24 taps you would cover most of the transformers out there. I've been looking for a kit that can do that and switch sources for a while now. The APOX was a little too pricey for me when it was released, and then it got discontinued. If you could do that fairly cheaply, I'm definitely interested.

What is the "other attenuator thread" you mentioned? I'll look for it, but I'd appreciate a link.

Thanks,
Saurav

 

[mcs]

That's what I thought. Mine has 18 taps, but I think if you built something with 24 taps you would cover most of the transformers out there. I've been looking for a kit that can do that and switch sources for a while now. The APOX was a little too pricey for me when it was released, and then it got discontinued. If you could do that fairly cheaply, I'm definitely interested.

I'll have a look at that tomorrow then...

What is the "other attenuator thread" you mentioned? I'll look for it, but I'd appreciate a link.

This one: http://www.diyaudio.com/forums/showthread.php?s=&threadid=46319

Best regards,

Mikkel C. Simonsen

 

[Saurav]

Thanks.

 

[mcs]

May I ask the path of the signal through the board? Just what components does the signal traverse?

Just the relay switches and the resistors.

I would hope it would only be one relay and the associated resistors at any given time.

No, it's 1-6 resistors depending on the setting. Otherwise you would have only 6 steps. You can make an attenuator like you describe up to 20-30 steps - otherwise you would need a lot of relays and space.

Best regards,

Mikkel C. Simonsen

 

[mcs]

That's what I thought. Mine has 18 taps, but I think if you built something with 24 taps you would cover most of the transformers out there.

I just checked - the Sowters need 26. Here's my attempt, if you haven't seen in the "moved" thread. You would just leave out all the resistors and solder in the transformers instead.

- quite simple if you ask me

I've been looking for a kit that can do that and switch sources for a while now. The APOX was a little too pricey for me when it was released, and then it got discontinued. If you could do that fairly cheaply, I'm definitely interested.

Have you seen this board: http://stiftsbogtrykkeriet.dk/~mcs/Remote3/Parts.html

Is it something like that? I'm planning to make an input selector only version of that board. You could then use that together with a volume control board and a small CPU board/control panel. You decide how fancy that has to be

I don't think it would have to cost as much as the Apox boards...

Best regards,

Mikkel C. Simonsen

 

[mcs]

I'll test it later tonight. Stay tuned...

I promised a "test report", so here it is.

I have done some measurements on the board. The attenuation is spot on - and I only use 1% resistors. The bandwidth is fine up to 20kHz at least, I haven't checked higher.

The crosstalk at 1kHz is -97.5dB at full volume. The worst case crosstalk is at the -7dB setting, and it's -82.12dB.

I do get a bit of hiss when I replace my normal preamp with the attenuator board. But I guess that's because of the high impedance (50k) and the lack of shielding. The board is just placed on top of my CD-player...

I get some small clicks when I change the position, but nothing that bothers me too much. I think both this and the hiss may also be caused by the very sensitive poweramp I use. I can clearly hear the music at the -63dB setting!

I'll try making a 10k attenuator also. I think the crosstalk data should be even better at low impedances.

Best regards,

Mikkel C. Simonsen

 

[MBK]

MCS,

any news on the relay board status? I have seen your website, looks neat and complete, just the 24 / 26 / whatever step relay attenuator boards to go with the input boards are missing

MBK

 

[mcs]

I'll add that tomorrow then

- it hasn't been tested yet though...

Best regards,

Mikkel C. Simonsen

 

[MBK]

That was quick...

MBK

 

[mcs]

I have added the second relay attenuator now...

Best regards,

Mikkel C. Simonsen

 

[Saurav]

OK, so what boards would I need for my transformer attenuator? Looks like I need RelVol2, in the 20 step version. I'll also need an input board and a control board, right? For the input I assume I should go with Input1, since InputVol1 has stuff for a motorized pot that I don't need. For the control board I'm not sure which one I need. Control1 doesn't have a display. Control2 can control a display, but looks like it uses a CPU of some sort that I'd need to program? This is where I'm not sure what I would need. Maybe I have it all wrong I guess I could use Control1, having a volume level display isn't critical.

Also, how easy would these be to set up and use? I don't think I can handle something that needs to be programmed

Other stuff... I see that you take PayPal, which is good. You can ship to the US, right? Are there any for-dummies instructions with the kits? Or can I bug you with questions when I can't figure out what to do with a board?

Thanks,
Saurav

 

[mcs]

OK, so what boards would I need for my transformer attenuator? Looks like I need RelVol2, in the 20 step version. I'll also need an input board and a control board, right?

Yes, but the input board is optional.

For the input I assume I should go with Input1, since InputVol1 has stuff for a motorized pot that I don't need.

I'll also make a small 3-input and mute board to connect to the four unused relay outputs on the attenuator board. That would be a lot cheaper, if three inputs is enough.

For the control board I'm not sure which one I need. Control1 doesn't have a display. Control2 can control a display, but looks like it uses a CPU of some sort that I'd need to program?

It does use a CPU of some sort yes (a Winbond), but you don't have to program it - you'll get it pre-programmed
I don't think many people have Winbond-compatible programmers anyway (I DIY'ed one).

This is where I'm not sure what I would need. Maybe I have it all wrong I guess I could use Control1, having a volume level display isn't critical.

You can basically use whatever you want, depending on how many features, flashing lights and knobs you want

Also, how easy would these be to set up and use? I don't think I can handle something that needs to be programmed

Just assemble the boards, connect the wires, power up and watch the smoke

Other stuff... I see that you take PayPal, which is good. You can ship to the US, right? Are there any for-dummies instructions with the kits? Or can I bug you with questions when I can't figure out what to do with a board?

Yes, yes and yes.

Best regards,

Mikkel C. Simonsen

 

[Saurav]

I'll also make a small 3-input and mute board to connect to the four unused relay outputs on the attenuator board. That would be a lot cheaper, if three inputs is enough.

Perfect. Yes, 3 inputs will be enough, and I don't need a tape monitor either. So how would this work... the IR receiver is on the attenuator board, and that drives the new input board through its output relays? So those are the only boards I would need? And a power supply of course. I have a universal remote control. If I set that to Philips then it should just automatically work with the IR codes your controller uses?

You can basically use whatever you want, depending on how many features, flashing lights and knobs you want

Well, everyone knows that blue LEDs make a component sound better, and flashing blue LEDs must be one more step up in sound quality Seriously, once I have a remote control I might as well add input selection and mute to it.

Just assemble the boards, connect the wires, power up and watch the smoke

Again, perfect Thanks a lot.

 

[mcs]

Perfect. Yes, 3 inputs will be enough, and I don't need a tape monitor either. So how would this work... the IR receiver is on the attenuator board, and that drives the new input board through its output relays? So those are the only boards I would need?

No, you will need some sort of control board. The chip on the attenuator board is just a shift register/relay driver. You could also connect three push-buttons and key in the data manually, but a control board will be a lot easier

I have a universal remote control. If I set that to Philips then it should just automatically work with the IR codes your controller uses?

Yes, unless it's very cheap and bad. I have had problems with some of the $3-4 universal remotes, but the $8 and up remotes work fine.

Well, everyone knows that blue LEDs make a component sound better, and flashing blue LEDs must be one more step up in sound quality

Then I think you should use a blue LCD display for maximum sound quality

Best regards,

Mikkel C. Simonsen

 

[Saurav]

OK, so I still need the control board, you're just replacing the 5 input + tape input board with a 3 input board.

 

[KT]

Mikkel,

Hi. I've been reading both here and on the TX102 thread and think that a remote control is very appealing.

In addition to producing a relay-based switching board, is it also possible to produce a board with a remote-controlled motor on it? The shaft of this motor would have a gear on it that would mesh with a gear on the shaft of a rotary volume selector switch.

I'm thinking of this because this solution would solve the issue of mechanical relay switching noise, which I brought up in the TX102 thread, and because I have a brand new Seiden switch that would be great to put a remote on.

So I guess my question is this: would it be better or more elegant to have a remote-controlled motor on a good rotary switch like a Seiden, or would it be prefereable to have a bank of relays? Either could be used with either resistors or transformers with some adjustment either way. I wonder which solution would be preferable?

I'm inclined to think a remote-controlled motor turning a rotary switch would be better as it avoids all the EMI radiation issues of the relays and avoids the mechanical switching noise, too. That is, of course, if the EMI generated from a small motor is actually less harmful that that produced by relays. What if the motor were disconnected when not in use, preventing EMI pollution - vs. a relay that's always powered on at all times. What do you think?

Also, with a motor turning a detented rotary switch, I wonder how you'd specify the step increments so that motor would drop the switch right into the detent each time.

Thoughts?

Best,
KT

 

[Saurav]

I didn't know you could get rotary seletor switches that could be turned by a motor. That could be a possible solution too.

 

[mcs]

In addition to producing a relay-based switching board, is it also possible to produce a board with a remote-controlled motor on it? The shaft of this motor would have a gear on it that would mesh with a gear on the shaft of a rotary volume selector switch.

Yes, that is possible. But I think it would be much easier to do with a non-detented switch, which would make manual control difficult. Perhaps using a stepmotor with 15° steps?

So I guess my question is this: would it be better or more elegant to have a remote-controlled motor on a good rotary switch like a Seiden, or would it be prefereable to have a bank of relays? Either could be used with either resistors or transformers with some adjustment either way. I wonder which solution would be preferable?

Driving a switch with a motor doesn't sound elegant to me
I think a relay switch is just as good as a rotary switch, and a lot easier to make. You don't have to worry about mechanical alignment either...

I'm inclined to think a remote-controlled motor turning a rotary switch would be better as it avoids all the EMI radiation issues of the relays and avoids the mechanical switching noise, too. That is, of course, if the EMI generated from a small motor is actually less harmful that that produced by relays. What if the motor were disconnected when not in use, preventing EMI pollution - vs. a relay that's always powered on at all times. What do you think?

What EMI radiation issue? A relay driven by DC doesn't radiate anything harmfull as far as I can see. There is a small magnetic field around the relay coil that's on, but what does that harm? And if it is harmful, wouldn't the magnets in a motor do the same harm? The magnetic field in the relay is constant, so it doesn't induce any noise in the signal - you need an alternating field for that.

Also, with a motor turning a detented rotary switch, I wonder how you'd specify the step increments so that motor would drop the switch right into the detent each time.

Use a stepper motor with the correct step size, or use an extra deck on the switch for creating switch-off pulses?

Thoughts?

It can be done, but I don't really see any advantages?

Best regards,

Mikkel C. Simonsen

 

[maxw]

WOW, you have some excellent stuff there!

If I understand correctly it all goes together very cleverly

So would this work?
A control2 controlling a ChipVol1 and an Input1 ?
If so, is the control2 compatable with HD44780 displays?
Does the control2 include the PIC chip and software to control the PGA2310?
Do you have to pay VAT if you are over seas?