Group Build: Dynafet

[naamanf]

For PCBs I have used Advanced Circuits. They have a pretty good deal on proto boards for $33 each with a min order of 4 that comes with another for free. $132+shipping for 5 boards.

https://www.33each.com/!33each1.asp

[luvdunhill]

Guys, I need to get a firm number by tomorrow for the number of populated boards, and the total number of TO-92 heat sinks I need to have manufactured. Please confirm with Icarium ASAP.

If you're interested in extras of the heat sinks above and beyond the group buy, it looks like the price will be $2.50 each. Yes, a little steep, but after playing around with these, I'm confident that they offer greater or equal performance to the dual devices, and I'm not really looking backwards at this point.

KG: I think the group would be more than willing to send you some of these as a thank you for the Dynafet design, since you expressed interest. Please PM me your address and we can go from there.

Here's a picture:

[Icarium]

Everyone's confirmed besides PFKMan. I'll mention the Thursday deadline to him.

Looks like we have everybody I'd expect to be in for Sowter transformers except for Digipete, looser01 and PFKMan. (I know Pars isn't interested. Also guessing Kevin Gilmore/Nate Maher are not interested).

Btw, luvdunhill since you have more group buy experience than me.. generally does the buy organizer have to distribute? Do you think we could include the Spanish guys and have Sowter ship direct to them? I don't know their interest though either way I guess.

[luvdunhill]

Do you think we could include the Spanish guys and have Sowter ship direct to them? I don't know their interest though either way I guess.

I have a feeling it will be cheaper for us to ship to them, if you know what I mean.

[Icarium]

Ha well if its cost effective for them to join with us... then I need to know if your team needs any Torpedo.

[Torpedo]

Are you planning to use the Sowters for the PS and the balanced to SE conversion or just for the second? I can't say myself, I need Picaudio or Hitori to show up.

On the other hand it depends on the savings and what Sowter says about sending some trannies to Spain directly, maybe it doesn't make it any more expensive for you, so it saves us the risk of paying custom duties for an European product and the sure cost of shipping from US. Trannies are heavy

[Icarium]

I think these transformers are pretty small.

[grawk]

sowter is for SE/BALANCED, it's not a power transformer

[Looser101]

Looks like we have everybody I'd expect to be in for Sowter transformers except for Digipete, looser01 and PFKMan. (I know Pars isn't interested. Also guessing Kevin Gilmore/Nate Maher are not interested).

Btw, luvdunhill since you have more group buy experience than me.. generally does the buy organizer have to distribute? Do you think we could include the Spanish guys and have Sowter ship direct to them? I don't know their interest though either way I guess.

I will not need any input transformers.

Thanks

[Icarium]

Thanks

[guzziguy]

Guys, I need to get a firm number by tomorrow for the number of populated boards, and the total number of TO-92 heat sinks I need to have manufactured. Please confirm with Icarium ASAP.

<snip>

Everyone's confirmed besides PFKMan. I'll mention the Thursday deadline to him.

<snip>

I'd love to get in on this but can't justify spending $2500 for another amp, even to myself much less to my wife. I'd have to spend even more as I don't have the skill to build this complicated of a project. I wish you guys the best of luck with this and my heart will be with you. I can't wait to listen to one of these.

[PICaudio]

Very good option. I'll wait for Picaudio's comments since he'll be building my amp. Maybe the spanish group sums to it.

I think it's a good option too, I haven't any problems to mount this controller boards.

-- o --

Rodrigo

[PICaudio]

Are you planning to use the Sowters for the PS and the balanced to SE conversion or just for the second? I can't say myself, I need Picaudio or Hitori to show up.

On the other hand it depends on the savings and what Sowter says about sending some trannies to Spain directly, maybe it doesn't make it any more expensive for you, so it saves us the risk of paying custom duties for an European product and the sure cost of shipping from US. Trannies are heavy

I don't want Sowters at this moment.

-- o --

Rodrigo

[Icarium]

Are you speaking for Torpedo and Hitoridekimasu as well? You have some time to decide for sure. It really depends on when luvdunhill wants to make the order or whoever is in charge of that. I'm guessing within a month?

I don't know for sure. Just as soon we you form a concrete decision let me know

[DigiPete]

Everyone's confirmed besides PFKMan. I'll mention the Thursday deadline to him.

Looks like we have everybody I'd expect to be in for Sowter transformers except for Digipete, looser01 and PFKMan. (I know Pars isn't interested. Also guessing Kevin Gilmore/Nate Maher are not interested).

.

No Sowters for me.

Thanks,

Pete

[Icarium]

K then that's that on Sowters for the US/Canadian bunch. Just waiting on the Spanish krew and then that group buy can go down whenever whoever is in charge is ready to coordinate the order.

[PICaudio]

Are you speaking for Torpedo and Hitoridekimasu as well?

I could not talk to them, it's only my opinion. These days were public holidays in Spain (carnivals) and I have been away from home.

You have some time to decide for sure. It really depends on when luvdunhill wants to make the order or whoever is in charge of that. I'm guessing within a month?

I don't know for sure. Just as soon we you form a concrete decision let me know

OK, thank you very much. I'm very busy with my work and I haven't thought about how to configure the I/O of my Dynafet.

-- o --

Rodrigo

[Torpedo]

I won't make things more complicated for Picaudio building my Dynafet, however the trannies can become handy when using a SE source to drive balanced headphones.

[Icarium]

Yeah that's the primary use case.

Okay I heard from you all about transistors.

Dynafet Group Order - Google Docs <- This spreadsheet represents how many boards you each want and how many sets on transistors you want (In the scale of boards worth like 4 boards worth or 2 boards worth etc).

If anyone notes any inaccuracy here please let me or luvdunhill or post here asap!

Thanks for your cooperation and hopefully the ball starts rolling soon

It's looking like we need 62 boards worth at the cost of 60 dollars per board I believe.

[Torpedo]

I've checked it. Did Hitori contact you and said he wanted 6 boards instead of 4? Maybe he wants some spares hahahaha.

[Torpedo]

We also would like 2 Sigma boards each, the transistors for the Dynafet and the parts to populate the S22, unless Picaudio states otherwise.

[Pars]

In my opinion (but I haven't actually checked the figures), getting the Sigmas as kits from Jeff at glassjar is probably cheaper (or as cheap) as buying everything as a group. Looking at his BOM spreadsheet where you can configure what you want, a sigma with board, but no transformer would be ~$66 plus shipping per kit. I can send or post the spreadsheet if anyone wants to see it.

[Icarium]

Yeah I am in talks with glass jar audio. He said it'd be ~67 dollars a kit without toroids and he might be able to give us an additional 15 percent off for a bulk order and is willing to handle shipping to people provided we give him a list.

If you wanna post the spreadsheet that'd be $$. I was going to do it after work tonight, but yeah that's in another ~8-10 hrs or so

The only logistics question is that his kits are tailored to very specific toroids with certain VA values.. if we want to things like run 2 boards off a big transformer or values not in sync with what he normally kits for.. do we need additional parts? If so what type? I imagine even if we need to buy some parts separately it will make going with glass jar audio worth it since his prices are so insanely low.

[Icarium]

I've checked it. Did Hitori contact you and said he wanted 6 boards instead of 4? Maybe he wants some spares hahahaha.

Yeah he wanted 2 spare boards... just boards though I think.

[Torpedo]

OK then, but please add the transistors to populate the 12 Dynafet boards and also the 6 Sigma boards with their parts for the Spanish gang.

I think that getting the S22 boards in kit form if it's flexible enough to let you choose your trannies can be a good thing. At 67$ doesn't sound very expensive.