[digger945]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif Seller audiotek168 has quad Alps Blue pots for pretty cheap: ALPS RK27 Attenuator Volume Control 10K Stereo/BALANCED - eBay (item 280249535919 end time Feb-19-09 05:36:19 PST) If you can find one in an actual auction, you can get them even cheaper.

I've bought a bunch of stuff on auction from this ebayer, cap's and holco's.
I gotta lead on what I believe is a much better stepper, if things pan out.

FallenAngel, I think you can get matched 74/170's from AMB's store also, and maybe Beezar, and he(Ti) mentioned to me subbing BC550/560's(for 389's and 109's) also, can't remember much, my computer crashed and I lost all the info and links to articles saved. I'm not familiar enough with the Dynalo to comment if those could be used within that particular circuit, all my reading and research is on the Dynahi, and has now evolved into the Dynamite.

I have found many many links to suppliers that, according to thier websites, have thousands and some tens of thousands of 389's and 109's in stock, but they have pretty high minimum order requirements, and do not deal with small potatos individuals like me. I find this kinda hard to believe, as it would seem like some enterprising reseller would buy some of these and sell to individuals. None of these supposed suppliers have prices either, you must submit an online request for further info. and a quote.

 

[FallenAngel]

Yeah, but they're a little expensive from them (though still reasonable), but when you need enough for 4 Dynahi boards, it's a matter of $50 (matched) vs $16 (unmatched).

 

[breizheau]

Pars,
i will use the PSU used for the Dynahi and provided by Dan. So i think the transformer is good.

 

[Pars]

Quote:

Originally Posted by breizheau /img/forum/go_quote.gif Pars, i will use the PSU used for the Dynahi and provided by Dan. So i think the transformer is good.

I was thinking about build one for the Dynahi I'm doing just for the challenge. But the $20 OPAs talked me out of, given the history of people blowing them and no post mortem cause identified yet. The sigma22 is just as good, easier and cheaper to build, so that is what I am going to use, even though I have Dynahi PSU boards since the group buy.

 

[digger945]

^Same here.

 

[breizheau]

I will try different PSU. As mentionned in the 1st post, i have also PSU PCB used to do my preamp. Several people in our french board used this PSU and they say it's quiet good !

 

[breizheau]

I found the schematic of the PSU i will use also to try....

The output voltage can be modify and the max current as well. What do you think ?

 

[breizheau]

Any remark or advise or....i don't know what about this PSU ?

 

[dgardner]

Quote:

Originally Posted by dgardner /img/forum/go_quote.gif Yes, there are still boards left over from the past group buys. -Dan

I also have matched pairs of the 2SJ74 and 2SK170 to replace the hard-to-find 2SJ109 and 2Sk389 parts if anyone needs some.

 

[Pars]

Quote:

Originally Posted by breizheau /img/forum/go_quote.gif Any remark or advise or....i don't know what about this PSU ?

Well, I don't know my ass from a hole in the ground about these sort of things (in other words, I would never try to design a high quality PSU myself).

It is not a tracking supply, meaning the rails do not track one another. The original Gilmore dynamic supply, the Dynahi supply and the sigma22 are tracking designs. Since you can adjust the CCSs via trimpots on the Dynalo boards, it probably isn't a big deal, though I prefer getting the offset very low through matching, and keeping the 2 CCS sides as even as possible, which helps ensure that voltage swing in either direction will be as close to equal as possible.

I can't comment on the noise performance of your PSU design.

 

[breizheau]

We received tje PCB from Dan (thx to him) and are ainting for the missing parts from Futurlec and Farnell FRance.

 

[bidoux]

I've sent an Email to dgardner a week ago. Is it normal that I haven't got any answer since ?
I'd like to buy one (or two if I mess up the first one) Dynalo board and maybe some transistors, seeing they are hard to find.
breizheau (un breton ? ) Could you tell me how much was the shipping cost ?
Thanks.

 

[breizheau]

Tiens, un PRESQUE Breton !

Dan has a life as well and sometimes he is away from home.
I paid 10 USD for my set of PCB (3 Dynalo PCB + 3 PSU). Ask him also about the Dale resistor.

Kénavo .

 

[nico2k3]

Hello

I'm building the Dynalo thanks to Breizheau, I'd have a question about the input loading method when using a relay attenuator (RelVol1C from Dantimax : Dantimax (elektronik) - Selectors_-_attenuators) : shall I do as if it was an ALPS potentimeter or using a fixed resistor (step 9 in Dan's .doc file) ?

Is there a difference between plugin this attenuator on the input or the output of the amp ?

Thank you for your help

Nico

 

[breizheau]

I sold my 1st Dynalo and decided to build the second one.
I talk about this amp with somebody and he gave me advices :
- [R18,R20],[R46,R50]=3,3k -> 15k (to reduce H3 from 0,13% à 0,008%)
- [R7],[R37]=1k -> 3.32k (gain)
- [C27],[C28]=10pF -> 22pF
- [R3 à R6],[R33 à R36]=200 -> 47,5 (only if you change R7 and R37)
 
My impressions : after changing R18, 20, 46 and 50, the sound is a little bit different. I don"t have "boomy" bass but they are deep now. It's nice.

The others mods don't change the sound so much as the first one.
 
You should try !!!!!!!!
 
Thx to Kevin for the schematic of course.
 
Cheers !
Olivier