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

[Russ White]

Originally posted by jimbo1968
I'm tempted, but the parts list means very little to me.

If someone said "You can get every component from xyz and it will cost about xxx dollars" then it would be an easy decision. A US source (online) is just as good as UK for me, better in fact as it will be cheaper.

Parts cost is largely up to you, and dependant on what you already have or can scrounge.

Depending on what quality components you buy you should be able to get the electronic components for less than $100, but I have not thouroughly sourced parts yet.

I will be checking into that though. Also, Brian Donegan is looking into the cost of parts kits.

mouser and digikey should have everything you need. Also some lower cost places like futurlec will have some of the parts.

[rabbitz]

Yeah... put me down for 1 and let us know when your Paypal account is running. Is there a parts list or BOM?

[Russ White]

Yes there is a parts list in the "REF" thread. I will also put it on the order page.

[BrianDonegan]

So, I have started building a parts list, so far from DigiKey and Mouser.

Slim pickings for boxed caps in the US, it appears. I think I can get them all, but they will end up being from a few different manufacturers. Mouser has started carrying Wima, but not much of a selection yet. Roght now I have (from memory) 1 Wima, 1 or 2 BC's, and 1 or 2 Epox.

An alternative would be some Panasonic film caps (not boxed) with the same pin spacings. Anybody have a problem with that, or should I just go with those. They are the same types used in the standard Leach amp, if that helps anyone decide.

Also, for the low-ESR EL's, I was thinking about the Panasonic FM types. They have a 40% lower impedance than the FC series, and better specs all around, but are for some reason cheaper (?).

[mwmkravchenko]

THe type and pin spacings are the most important things.

Trying to etch one of these babies in the near future!

No time AHHHHH!

MArk

[jimbo1968]

Originally posted by Russ White
Depending on what quality components you buy you should be able to get the electronic components for less than $100, but I have not thouroughly sourced parts yet.

I will be checking into that though. Also, Brian Donegan is looking into the cost of parts kits.

As it appears to be a non-trivial task for Brian, it's a good job I didn't assume I could do it myself.

I'll probably put myself down for a board once the order page appears, as long as there's a kit or kit list.

I need to re-read the thread to work out why I would want to build this. Presumably it's for the joy of experimenting, and so I can compare the result to my (soon to be built) standard lm3886 chipamp.

[Russ White]

Here is the link to the order page. Order early, and order often.

Mauro's Reference GC GB order page

The schematic, parts list, and the silkscreen for parts location for the board is also available from the page.

Thanks,
Russ

[dw1narso]

As it appears to be a non-trivial task for Brian, it's a good job I didn't assume I could do it myself.

I'll probably put myself down for a board once the order page appears, as long as there's a kit or kit list.

I need to re-read the thread to work out why I would want to build this. Presumably it's for the joy of experimenting, and so I can compare the result to my (soon to be built) standard lm3886 chipamp.

Hi Guys,

What I mean as the parts kit is the optimum (or maybe a good start) parts for the kit.

I know that maybe I can get any resistors/caps in my country. But whether it will be good for the system or not that is a question.

My other reason is, if we start with very-very different parts, how can we tell that we are listening to the same kind of sound from the amp. And that would be the real question.

I learn hard about this while trying to tweak Brian GT's LM3875 chip amp kit (basic). I changed the parts with some cheaper and even some more expensive parts. Everytime I did that, the sound changed a lot! So I learn that on some part of the circuit, $1 Kiwame resistor can sound worse (a lot worse) that 10cents Panasonic resistor. At the end, I put back all the original parts. The are the optimum parts for it; GC magical midrange has been delivered with just of them. And I will be very careful now on swapping parts, especially trying to away from boutique parts.

And, as I mention previously... I cannot just get Panasonic caps or resistors, or even phoenix metal films one in my country... the available part is always on extreme: 1 cent resistor or $1.5 Rikken, and other case is almost always like that....and that make me envy of you guys living in DIYing heaven country like US/Canada...

REgards,
---
David

[BrianDonegan]

Hi,

This is all on paper right now, but so far I am using Panasonic film caps (ECQ-B series), FC series Electrolytics, FM series for the low ESR 220uF, and TS-U series for the PS caps. (Incidently, I couldn't easily find a 10000uF 40V cap for the PSU in 30mm, so I opted for 12000uF 50v version. Should be fine.) I have selected an ECQ-E series for the input cap.

For the 3886, I opted for the insulated TF, so it would be easier to mount, since there are no readily available pads or mica that fit the chip, and I didn't want to custom cut anything for the kits. As I said, this is all just on paper right now, so anything can change.

Since we only have the original manufacturer name for a couple of the parts, making an exact copy will not be very easy. If anyoine has good suggestions for substitutions, I am glad to hear them. I would like to keep it with the larger suppliers to make life easier. I'll post my list in a day or two.

[Russ White]

Good work Brian!

I managed to find the Wimas, but not through Digikey or Mouser. I also sent the entire parts list to a couple distributers to see about getting bulk pricing.

When I get something I will share it with you, maybe we can put our heads together.