[mcmurray]

Hey guys, I've been out of the DIY game for a while now, but I'm thinking about finally getting around to building a dynahi. I've had PCB's for ages and with the release of the HD800 I should get on with it.

How does the dynahi stack up against new amp designs i.e. B22 etc. Is it still a contender for the best solid state amp? What other high end solid state designs should I be considering?

 

[MASantos]

Of course!

A design doesn't get worse with age

 

[digger945]

I don't know but I'm fixin' to find out what a Dynamite sounds like in another week or two.

 

[mcmurray]

Quote:

Originally Posted by MASantos /img/forum/go_quote.gif Of course! A design doesn't get worse with age

I understand, but have there been any ground-breaking designs recently that are better?

 

[FallenAngel]

Aside from the Beta22 being an incredible design, I don't think so. The Dynahi is still one fantastic amp. I'm definitely considering building one, but I swore not to start it before I have my balanced Beta22 finished.

 

[MASantos]

Not really.

The dynahi actualy uses one particular dual complementary j-fet (don't remember the exact number, 2sk...) on the input stage that had some of the best noise and performance figures, but today it is almost impossible to get there.

AMB's B22 has provision to use a new dual j-fet but only one of the versions (PNP or NPN) is currently available, so you need to build it with matched pairs of single j-fet which in teory(and probably in the real world, I don't have the knowledge to answer to that) don't have the same performance.

The B22 is also easier to build because of the easier heatsink assembly, part availability, great website and support that AMB provides to the DIY comunity. These don't actually relate to sound quality, but are factors you need to account for when thinking about a build!

Manuel

 

[mcmurray]

Quote:

Originally Posted by MASantos /img/forum/go_quote.gif The dynahi actualy uses one particular dual complementary j-fet (don't remember the exact number, 2sk...) on the input stage that had some of the best noise and performance figures, but today it is almost impossible to get there.

Are you saying that this dual complementary j-fet is hard to find?

 

[Uncle Erik]

Are the chips still available for the Dynahi? I stuck some away before the Great Tube Seduction, but I've got some spare boards. If there's a supply for the chips, I might have to build all of them out.

 

[DigiPete]

The DynaFet, Kevin Gilmore's latest creation (Dynahi successor) is currently the subject of a group buy/build somewhere

 

[holland]

where?

 

[mcmurray]

Quote:

Originally Posted by DigiPete /img/forum/go_quote.gif The DynaFet, Kevin Gilmore's latest creation (Dynahi successor) is the currently subject of a group buy/build somewhere

Now you have my attention

Has anyone here built one?

 

[DigiPete]

Quote:

Originally Posted by mcmurray /img/forum/go_quote.gif Now you have my attention Has anyone here built one?

I doubt it... except Kevin Gilmore has built his prototype, and he did have an old thread on it in head-wize DIY area.

 

[FallenAngel]

Saw that, looked nice, that was 2 years ago though.

 

[digger945]

Quote:

Originally Posted by MASantos /img/forum/go_quote.gif but today it is almost impossible to get there..... so you need to build it with matched pairs of single j-fet which in teory(and probably in the real world, I don't have the knowledge to answer to that) don't have the same performance.

I think that singles can exceed the duals performance and matching.

Quote:

The B22 is also easier to build because of the easier heatsink assembly, part availability

You can say that again, especially if you doing it yourself.

Quote:

Originally Posted by mcmurray /img/forum/go_quote.gif Are you saying that this dual complementary j-fet is hard to find?

Obsolete.
Linear Devices has a replacement for the 2SK389, the LSK389, but everyone is waiting for the complimentary LS
J109 to come out, including those who are looking to build the DynaFET.

 

[mcmurray]

According to http://djgardner.com/headphone/gilmore/ 2SJ74BL and 2SK170BL can be used as a replacement for the SK109BL and 2SK389BL.

I think I'll go ahead with the build.