Pass Pearl PCBs and related parts

[luvdunhill]

That's quite the test rig!

Looks like we will have some very nicely matched transistors

So how does one go about using the 9v battery, and, are there benefits?

well, the 9v battery can be used in place of the zener diode to provide a voltage reference. I have no idea if there are benefits, some people posted at DiyAudio think so, some don't. I'd have to try both to really comment further though.

[luvdunhill]

I thought I had already uploaded this .. oh well, I made some progress on Monday night:

[swt61]

^

Very nice Marc!

I've gotten the case mocked up. It's a little unorthodoxed, because I had to suspend the second board from the top of the case. This was necessary because the standoffs were in the way otherwise. I don't actually have the second board on hand, so you'll have to use your imagination there. That's it in Marc's pic above.

I ended up mounting the toroids in a piggy back configuration. The caps and rectifiers were a bit snug, but there is enough room.

This was my first case up job, so go easy on me.

[DigiPete]

^

Very nice Marc!

I've gotten the case mocked up. It's a little unorthodoxed, because I had to suspend the second board from the top of the case. This was necessary because the standoffs were in the way otherwise. I don't actually have the second board on hand, so you'll have to use your imagination there. That's it in Marc's pic above.

I ended up mounting the toroids in a piggy back configuration. The caps and rectifiers were a bit snug, but there is enough room.

This was my first case up job, so go easy on me.

Looks nice. I hope you don't have any noise issues with the transformers being so close to the boards.

[n_maher]

Damn those be some long-ass standoffs!

[luvdunhill]

Steve:

Looks great. How will the heat sinks fit? I bet you're going to have to shave 0.25" or so off of them...

DigiPete:

Yeah, this is a worry, but the toroids will be a considerable distance from the input, which is the most sensitive anyways. I think he'll be fine. Otherwise, anyone have some big ass tuna cans?

[swt61]

Damn those be some long-ass standoffs!

Yeah they are. The heatsinks are pretty tall, so that's why such long standoffs.

Steve:

Looks great. How will the heat sinks fit? I bet you're going to have to shave 0.25" or so off of them...

I think they're going to work without shaving them. If you'll notice on the bottom of the long standoffs I've put some nuts, those should give us the space needed.

Looks nice. I hope you don't have any noise issues with the transformers being so close to the boards.

Me too, but we'll solve that problem if it occurs. I'm not opposed to a separate case for the toroids if necessary.

[grawk]

http://www.goegood.com/

Over at DIYAudio, someone in the icepower order thread said they got a chassis from them that looked good and cost about $30...

[grawk]

http://www.goegood.com/

Over at DIYAudio, someone in the icepower order thread said they got a chassis from them that looked good and cost about $30...

http://www.diyaudio.com/forums/showthread.php?threadid=126506&perpage=25&pagenumber=7

[DigiPete]

I thought I had already uploaded this .. oh well, I made some progress on Monday night:

Marc,

I see you got the auricaps. Darn, I shouldn't have let you talk me into the M-caps

When are we getting the transistors and replacement zeners?

Cheers,

Pte

[n_maher]

http://www.goegood.com/

Over at DIYAudio, someone in the icepower order thread said they got a chassis from them that looked good and cost about $30...

diyAudio Forums - FS:B&O ICEpower 200ASC modules - 20PCS

I don't think that included shipping Dan, which would probably double the price of that chassis. Still not a bad deal at $70sh (it's $35 iirc) but I don't personally like the idea of shipping a chassis that far.

[luvdunhill]

Marc,

I see you got the auricaps. Darn, I shouldn't have let you talk me into the M-caps

When are we getting the transistors and replacement zeners?

Cheers,

Pte

nope, those are Steve's. I have something totally crazy lined up for mine... waiting for some parts to arrive. Let's just say that I have 100 or so caps per board.

The replacement zeners shipped on Friday, as well as a few more parts. I have some matched parts on hand I can ship out for the "over eager" They're matched by Idss, which is sorta the "normal" way of doing things. Anyways, maybe I'll make my first shipment on Friday of next week? The next week I'll be on a business trip to visit "The Evil Empire" in Seattle, so I'll be out of town...

Have you decided on a case, or perhaps tested the unregulated supply portion of the circuit? If you're going to do some sort of LEDs, I'd attach them to this portion of the circuit, before the boards.

[DigiPete]

Let's just say that I have 100 or so caps per board.

The replacement zeners shipped on Friday, as well as a few more parts. I have some matched parts on hand I can ship out for the "over eager" They're matched by Idss, which is sorta the "normal" way of doing things. Anyways, maybe I'll make my first shipment on Friday of next week? The next week I'll be on a business trip to visit "The Evil Empire" in Seattle, so I'll be out of town...

Have you decided on a case, or perhaps tested the unregulated supply portion of the circuit? If you're going to do some sort of LEDs, I'd attach them to this portion of the circuit, before the boards.

I have not decided on a case yet, probably two Par-Metal series 20's.

I will run it uncased for a bit.

I will be hooking up the psu (uncased) today to see how some voltages are measuring up.

Count me 'over eager'

[luvdunhill]

I have not decided on a case yet, probably two Par-Metal series 20's.

I will run it uncased for a bit.

I will be hooking up the psu (uncased) today to see how some voltages are measuring up.

Count me 'over eager'

excellent!

[DigiPete]

100 caps per board

Please explain

[luvdunhill]

100 caps per board

Please explain

I have plans to use styrene box caps for the RIAA filter and need to parallel "a few" to get the right values. We'll see once they get here if this is feasible or not.

[DigiPete]

Hooked up the power supply to one of the boards, soldered in the zener at the 9v battery holes,

Vin = 46.0 Vdc coming from the big cap

at R8 = 29.66 v

at D1 = 9.156 v

no voltages downstream of the zener seem to match, maybe because of transistors that are missing??

[luvdunhill]

Hooked up the power supply to one of the boards, soldered in the zener at the 9v battery holes,

Vin = 46.0 Vdc coming from the big cap

at R8 = 29.66 v

at D1 = 9.156 v

no voltages downstream of the zener seem to match, maybe because of transistors that are missing??

yes, that would make sense...

[DigiPete]

yes, that would make sense...

Is there a way to trim the voltage coming out of the regulator stage?

A pot across a certain resistor?

[Nenso]

Hey guys, everything looks nice so far, especially Steve's wood/metal hybrid case. I was wondering if it is wise to build the preamp (some parts of it) before I get a case? Or is that a very bad idea?

[luvdunhill]

What voltage are you getting across R2?

[DigiPete]

What voltage are you getting across R2?

83mv

[luvdunhill]

you're drawing less than half the current you will when the board is populated. I bet your voltage will be fine once everything is up and going.

[cetoole]

I am with luvdunhill, if the v+ is off when testing without a normal load, I wouldn't be surprised at all. This regulator has a pretty low level of gain, so will have a non-negligible output impedance. Plus, then you have the tolerances of the feedback resistors, transistors, and especially the zener diode or 9v battery. Besides, if you are at 29.66v, instead of a "normal" 29v, that is really just over 2%, and wont make a significant difference. If you really must trim it though, R10 and R11 are the regulator feedback resistors, and adjusting either of their values' will change the output voltage. I wouldn't try doing this before the rest of the circuit is in though, and really, probably would just leave it be anyways.

[DigiPete]

Thanks cetoole.