Group Build: Dynafet

[j4cbo]

omg, a board designed by committee

It's not so much "design by committee" as "design by kitchen sink"...

[DigiPete]

J4cbo,

When able can you get me an official parts list with component numbering and values, hard to read those off the diagram.

When that is done, I will start putting together the passive component buy.

Cheers,

Pete

[luvdunhill]

J4cbo,

When able can you get me an official parts list with component numbering and values, hard to read those off the diagram.

use the schematic, it will be much easier than looking at the board silk, and much less error prone.

[Icarium]

Haven't verified with Luvdunhill yet... but I believe input transformers do need to be locked down today. I'm not sure what the latest situation is.. I heard something like sowters might be on hold for awhile, but I heard Cinemags are moving forward very soon since the diyaudio community is involved on that one.

I'm sure luvdunhill will clarify, but if you have yet to confirm an option please do so now. Check the spreadsheet as I know some of you had expressed interest with Sowter but that was prior to cinemag being an option.

Like right now I have nothing down for Team Spain.

[Torpedo]

Looks like Team Spain will go for the encapsulated Talema input trannies. Good enough, locally available and well priced. However I'll have Picaudio to have a look and decide about it.

[Icarium]

Okay cool sounds good.

Then all that's left is for Nate and the rest of my group to come to a decision (Morphsci/j4cbo) I think Pfkman has decided to go none.

[Pars]

Looks like Team Spain will go for the encapsulated Talema input trannies. Good enough, locally available and well priced. However I'll have Picaudio to have a look and decide about it.

I thought those were the power transformers?

[Icarium]

True this is for the input transformers which is for the single ended/balanced and vice versa business.

You guys previously has expressed interest in sowters, but those may or may not be off the table currently (Pending verification from luvdunhill).

Cinemags are ~37 bucks each and you need 2.

[DigiPete]

use the schematic, it will be much easier than looking at the board silk, and much less error prone.

Marc,

I assume you mean this

http://b.j4cbo.com/temp/gbf2.0rc1-sch.png

If this is verfied accurate, I will use it. I thought some part numbers were mangled, but I will look at it again.

Pete

[n_maher]

Yeah, I'm out for the transformers. The DIY fund is bleeding bad right now...

[Icarium]

No worries. Good luck with the bleeding :/

[Torpedo]

Yep, my wrong, the Talemas are power transformers (so input into the PS) but won't substitute the Sowters or anything else for the SE/balanced conversion. I think we are not using them, or if needed, would be purchased directly to Sowter in UK. I think all of the Spanish Team members have balanced sources.

Anyway, I'm waiting for Picaudio's thoughts though

[Icarium]

Okay so pending on PICAudio and then it's just J4cbo ;p

[atothex]

Dumb question: these transformers do transformation in both directions?

I need these for balanced source to single-ended headphones, and the same ones do single-ended input to balanced headphones?

[digger945]

No, you won't need these to use a balanced source with SE amp/headphones.

[Torpedo]

You shouldn't need it to use a balanced source to feed SE headphones, in this case you'd be using just 2 of the 4 boards on your Dynafet. You need the trafos to use a SE source to properly feed balanced phones using the 4 boards.

[PICaudio]

I don't want the sowters, in this moment I use only the balanced outputs of my DAC, I don't think I will use SE outputs.

-- o --

Rodrigo

[Icarium]

Okay sounds good. Just j4cbo then!

[grawk]

I'm in on the cinemags as per the wiki, but I appreciate any updates, in case I don't find out for some reason.

[Icarium]

Okay luvdunhill heard from everybody.. looks like we want 12 transformers (6 pairs). I still have you listed as wanting a pair of sowters, but I figure that's under your own control.

That's it then.

Also just checking in.. anyone still in flux with Glass Jar Audio or is everyone all paid up?

[grawk]

I don't want the sowters, just the cinemags

[Icarium]

My bad.. in that post "you" meant Luvdunhill.

[Icarium]

Talked with Jeff of Glass Jar he said he had received payments for Team Canada (Looser101), luvdunhill, Team Jacob, Team Spain and has shipped the shipments.

[Torpedo]

The Spanish Team has been thinking about how to build their Dynafets and we have agreed to try the following:

- Making it balanced (4 boards) in such a way that when used in SE, it can work as a double SE amp, with separate outputs and volume controls (but sharing the same input signal)

For this we have thought that using separate volume controls (for each channel in balanced and each amp in SE) is needed.

We'd like to use the J4cbo controller board with its SMD attenuator, however we don't know if it can be configured as needed to have the separated SE amps in the way described above. Any thoughts or suggestions?

[naamanf]

Why not use it as a double SE amp with the same volume control as balanced? Only reason I can see to do separate volume control would be to volume match two sets of different headphones. Seems like a lot of work for something you might try once.