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Mauro Penasa's INV GC/REF GC group buy.

I have obtained the gracious permission of Mauro Penasa to have PCBs made of the chip amps he has made public on this site.


The boards will be as he designed them with solder mask and silk screen.

I am going to try to keep the price right around $20 depending on my actual cost.

Please let me know if you are interested soon, as it takes 2-3 weeks to get the boards made.

These are very practical designs which work well for making both integrated amps and stand alone power amps. Also, everything is on the PCB excpect the trafo, so no need for a seperate PS board.

The amps have already been prototyped and tested as you can read in the threads.

Here is an image of Mauro's prototype of the NIGCWIPS:

Order date.

I will set up a paypal account and begin taking orders sometime in the next week or two. So, no its not too late.

I would like to get payment prior to ordering the boards since this will be a small batch with very little margine.

Once the boards are ordered I should have them in about 2-3 weeks. At which time I will mail them out.

I am willing to ship outside U.S. as long as I am able. I have never shipped out of U.S. before so I am not sure what is required besides extra postage. I will charge postage and packing fee that is in line with the actiual cost to ship. Probably around $5 for US orders.

It looks like most people want the REF boards, so maybe I will focus on those for now.

I looks like there is demand for 5 or 6 of them besides mine, so maybe I will go ahead and order a dozen. I would really like to order 20-30 of them as the cost goes down significantly.

This is a very different and inovative design, and not "just another gainclone". I think its one a lot of us would like to try.

Please get the word out, and post if you are interested. I will set up a web site for reserving your boards soon.

If enough people are interested I may also be willing to create a parts kit.
Hi Russ,

since finding good component in my country is the biggest challenge for DIY-ing... (it is very difficult just to get panasonic FC cap or resistors) I would be interrested to the ref board if it comes as a kit... with all the required components...

So, any followers to build it as a kit?



Paid Member
2002-09-04 11:27 am
Silicon Valley
Re: Order date.

Russ White said:
I looks like there is demand for 5 or 6 of them besides mine, so maybe I will go ahead and order a dozen. I would really like to order 20-30 of them as the cost goes down significantly.

Please get the word out, and post if you are interested. I will set up a web site for reserving your boards soon.

I'd be interested in 1 or 2 boards to help move this along.
Pricing update.

Since most of the the emails/posts have requested the "REF" design I will limit the current order to that design.

Here is how pricing breaks down right now:

If I order 10 pieces:

$22.50 per stereo board.

If I order 20 or more pieces:
$19.75 per stereo board.

In either case shipping/handling charge will be $5.00 per order for U.S. orders for up to 8 boards.

I will have to deal with orders outside the U.S. on a case by case basis. In any case payment will be accepted through paypal.

Lets see if we can get the order size up to 20 pieces, as that brings them under twenty bucks. That is a great price for these boards.

Does anyone have a preference for color? I was planning on ordering red, but I am open to suggestions. I may even be able to get a couple of different colors. I will ask.

I am not opposed to doing two sided boards, but I am not sure we have time to get it in for this round.

Plus this is really Mauro's design and not mine. I would kind of like to use his original work, just to have a few around.

I am not good enough at eagle (yet) to do it myself. Plus I think the board is too big for the free version which is all I have.

It seems the count is around 10 right now... maybe 12.

At this rate I will likely get the order in later this week.

Thanks for your interest in this by the way.


Quick update:

I only have the option of getting green boards right now. Later (if I can get a lrger quantity) I may be able to get other colors, but the first order will have to be green.

The good news is I am able to get very high quality boards specs as follows:

1.6mm FR4 boards
2oz copper
HASL finish
Green color

I will start accepting payments very soon for this first batch. Keep in mind that while this is a tested/protoyped circuit that this is the first production batch of these boards from this manufacturer I will have received. They should be just fine, but there is an outside chance of manufacturing defects. I am using the Gerbers provided by Mauro.

I ordered a batch a couple weeks ago of a dozen of each of the designs but they were made locally and sent to some college friends for school projects. I did not have any parts for building one yet so I let all of those boards go. Those boards were pretty expensive. I would have had to sell them at $25 just to cover my cost, so I decided not to use that manufacturer. Also, the boards were not as good as these should be, in fact the boards were very thin. These should be quite a bit better.

Lets get a few of these built, and then based on community input evaluate the value of modifications such as dual layer.

The single layer board is a very attractive solution because it does help keep the cost very reasonable while only adding a few jumpers which are easy.

I will post the order page address soon.