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

[Russ White]

My primary web server is back up, so you can use the primary order page nage now.

Which is:
order page

 

[BrianDonegan]

I ordered the parts last night, and the heatsinks on Saturday morning. As soon as I get the final shipping numbers, I will send out the invoices. Hopefully later this afternoon.

 

[Russ White]

Excellent! Good work Brian!

 

[BrianDonegan]

GaryB-

Please send me an email at bdonegan at gmail dot com. Thanks.

 

[awashi]

Brian, thanks for the effort!
Will transfer the money tomorrow hopefully or the day after, because i ran out of online banking transaction code thingies and have to drop by the bank.

Time to start salvaging parts for the PSU =)

 

[awashi]

Anyway, are we building Variant 2 of Mauro's design? (my_ref_variant2.pdf)

 

[Russ White]

Anyway, are we building Variant 2 of Mauro's design? (my_ref_variant2.pdf)

Nope, this GB is for variant 1, though much (actually all I think) of varient 2 can be done on the same board.

 

[BrianDonegan]

...and I think all you need for the PSU is a transformer and a power switch. Everything else is on the board.

 

[awashi]

Ah ok well variant 1 is fine, using speakers with 6ohm anyway
Hope to be able to use the transformer of my 20 years old amp i got from the trash (got thrown away because of blown fuses..)

Reading the Naval electrical engineering training series thingy at the moment in the hope to assemble this thing without wrecking havok

Edit:
Is it any use to enclose the transformer in some mu-metal to minimize electro-magnetic emissions into the other components?

 

[BrianDonegan]

I'd try it without shielding first, rather than going to all the expensive if you don't need it. Often, if you do experience some interference, wou can re-orient the transformer to minimize or eliminate it.

 

[BrianDonegan]

Just an update on the kits...

The parts orders should be arriving on Monday the 11th.

I had to order some more heatsinks, but hopefully they will be here early next week as well.

I will try to get the orders shipped by the end of next week, assuming you are paid up by then

I have sent all the invoices out.

That's all for now.

 

[BrianDonegan]

I will also be including in the kits a pair of DIP-8 sockets, both to make soldering safer, but also to allow op-amp games later on.

I also want to say that Russ Boss (the heat sink guy) has been incredibly helpful and flexible. See his heatsink auctions here. I can't recommend him highly enough. Pass the word around.

 

[BrianDonegan]

Final BOM ( I think - will double check after sleep ). sleep....

 

[BrianDonegan]

Seth-

Your email does not work. It get's bounced back. Email me directly at bdonegan at gmail dot com.

 

[awashi]

Paypal informed me the money for Brian and Russ got sent today!

Thanks for your efforts guys!
Would be a 100VA transformer be sufficient for powering the amp or should i plan for some more headroom?

 

[Russ White]

Would be a 100VA transformer be sufficient for powering the amp or should i plan for some more headroom?

300 VA is the smallest I would go, but 250VA would probably be OK. I would get 400-450 as they only cost a few bucks more. I buy mine direct from Avel. You save a little over getting them from parts express.

 

[awashi]

Hmm Avel being a good brand? Thought about going 500 and ordering a cheap 100 along with it, but if it's no use..
Does Avel ship to europe?

 

[Russ White]

Yes, Avel makes nice toroidal trafos. I am pretty sure they will ship to you, but you may want to email them to be sure.

 

[BrianDonegan]

awashi-

If you contact them, as if there would be a volume discount on these (24-0-24). I didn;t think to go directly to them. Perhaps I could add this to the group parts buy, if it would be cheaper.

 

[BrianDonegan]

Transformers

So, I spoke with the folks at Avel. They have a 330VA 2 x 25V transformer for $45.71 each. If we order ten of them, the price drops to $42.10 each. Parts Express has the same model for $47.67.

Will we save money as a group buy? Maybe. Shipping may end up negating the savings. It may be easier though.

I'll add a column to the Wiki, and you can let me know if you want one. I'll be ordering one for myself anyway, and I can easily get more and add to your kit. They have them in stock.

Wiki: http://www.diyaudio.com/wiki/index.php?page=Mauro+Penasa+GC+Parts+GB