Vortex

KG Balanced Dynahi build discussion thread

610 posts in this topic

Funny thing about the Asian forums, the people selling the Rudistor stuff have a huge presence there.  When the SR-009 first came out a guy was claiming the Cirolian was an excellent match... that he just happened to sell said amp was naturally not a factor. :laugh:  

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I tested all the transistors before stuffing the boards but I did it with one of those DMM hfe testers I think my testing is not very reliable.

I have already ordered a new set of boards from Lil'Knight so I will definitely continue this project but before continuing I need to buy a good DMM and one of those transistor testers.

I was thinking of buying this one:

 

http://www.peakelec.co.uk/acatalog/dca75-dca-pro.html

 

Anybody has any experience with it? Seems a little better than the DY294.

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DCA75 PRO definately looks interesting and much more capable than the DY294. It can test MOSFETs, JFETs and some simple curve tracing, which the DY294 can't do. However, what's with the minigrabber thing, especially because they are simply soldered onto the board with no strain relief at all...

 

EDIT: I guess minigrabbers are easier to use for testing two in one or canned packages.

Edited by jwzhan

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Actually I think it's better because you don't have to touch the body of the device so no risk of heating it you just put it on your desk and grab the leads.

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looks like a nice tester.  But it can't test the high voltage stuff.

I will buy one anyway.

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You must have looked at something different.. I don't think the Amphenol plugs for my T2 umbilical cables was anywhere near $100/ea, more like $30/ea...

 

http://se.mouser.com/ProductDetail/Amphenol-Industrial/97-3107A-14S-6P/?qs=sGAEpiMZZMv%2fye0hRulZR7Hv1MjqEjMsBwm8X4dldec%3d

 

Any tips on a similar? Metal construction. Not too bulky connector, etc?

 

I appreciate the help guys. The HARWIN-ones looked nice, but a bit too bulky. I'm looking for something more "classy" but well-built.

 

Thx!

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Something like this?  I use these and they are ok in terms of build quality. 

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JAE makes some pretty decent connectors. These were used for the HV umbilical on a Counterpoint preamp I used to own. Check the voltage rating though if you need above 300V or so (though mine was running at 425V... good designer :rofl: )

 

http://se.mouser.com/ProductDetail/JAE-Electronics/SRCN6A21-16S/?qs=sGAEpiMZZMvwyOPDUMfDH5gn%2fEwOZw6DcRDCXriNW8o%3d

 

http://se.mouser.com/JAE-Electronics/Standard-Circular-Connector/SRCN-Series/_/N-1z0zl5cZav49jZ1yzvw9y

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Something like this?  I use these and they are ok in terms of build quality. 

Did you try them for HV stuff? I bought some of them way in the past but never tried to see how they work with HV.

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Yup, I used them on most of my amps.  Tracked down the data sheet at some point and they are rated at 500V. 

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Yup, I used them on most of my amps.  Tracked down the data sheet at some point and they are rated at 500V. 

Good to hear that. I did see the 500v rating but not totally sure if it's trustworthy enough...

 

The JAE looks great for the money. For the T2 or KGSSHV level, best ones you can score is the ITT Cannon, even more bulky and heavy duty than the Amphenol.

I am using some Japanese made connectors for the T2. They are just as good as the Amphenol but a bit cheaper. Adding a nice mil spec sleeve will make some bad-ass umbilical cables.

 

6955576579_8e89ba07e4_z.jpg

Edited by Lil Knight

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I finally have decided to declare failure on sourcing jfets, so this should be happening soon.

 

http://gilmore.chem.northwestern.edu/dynahibal7.jpg

 

uses that340 input bipolar chip

 

needs serious checking

 

mje15034/mje15035 are probably a better sounding set of outputs

Edited by kevin gilmore

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Is there a reliable source for the needed sand for this board?  I'm starting to think that good old power transistors are a thing of the past.  Seems that anything I look for is end of life now.  My tube projects are looking much more likely now because of this.

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that is the point of this new board.

 

all the sand is mouser available.

 

but in general the semiconductor companys are all getting together

to make sure decent audio is a thing of the past.  What good

are the new lateral mosfets, and the monster bipolar transistors

if you don't have the parts for the front end.

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that is the point of this new board.

 

all the sand is mouser available.

 

but in general the semiconductor companys are all getting together

to make sure decent audio is a thing of the past.  What good

are the new lateral mosfets, and the monster bipolar transistors

if you don't have the parts for the front end.

 

This might be a moronic question (but bear in mind that I'm a total newb in amp design and I'm trying to learn)... But will it sound the "same"?

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as close as I can come with available parts.

 

The that340 really is as good or better for noise

than the k389/j109. only difference is lower input

impedance, which is already low due to

supersymmetry anyway.

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Is there going to be a new power supply as well?  i know that the Sigma22 can be used just wondering if you were going to do an on board psu to match the amp boards.  Looking forward to this one.

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And what about a tube input stage? Would it work with the dynahi design?

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not unless you have some anti-tubes that work with protons.

 

seriously why would you want to do something like this?

because other people are stupidly adding tubes as the

front end which add extra noise and require extra power

supplies and tricky methods necessary to dc couple to

the output of the tubes etc...

 

If that is what you want, there are plenty of things

out there already.

Edited by kevin gilmore

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i will start on an on board power supply version this weekend.

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not unless you have some anti-tubes that work with protons.

 

seriously why would you want to do something like this?

because other people are stupidly adding tubes as the

front end which add extra noise and require extra power

supplies and tricky methods necessary to dc couple to

the output of the tubes etc...

 

If that is what you want, there are plenty of things

out there already.

 

I'm sorry I didn't want to say something stupid. I don't fully understand complex circuits like this.

Thank you very much for all your work.

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