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goldenreference high voltage power supply (GRHV)


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12 hours ago, johnwmclean said:

Teehee...
I was kind of thinking this was completely out of character for James.

Meanwhile I bought some C2M1000170Ds from eBay and kind of resigned them to be fakes...

They’re looking a bit beat up from being jumbled around, but I think the gamble paid off.

IMG_5982.jpeg

time to get out the dca75 and dy294. Your photos look consistent with my known good from mouser. If they are fakes they are extremely good.

 

Edited by jamesmking
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breakdown voltage is ~1510v (data sheet spec is 1700v min)
but limited by the dy294 1500v between c and e
I'm fairly confident they are genuine

funnily enough the eBay source I bought from is the same listing starcat referenced with the fake images

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8 hours ago, johnwmclean said:

breakdown voltage is ~1510v (data sheet spec is 1700v min)
but limited by the dy294 1500v between c and e
I'm fairly confident they are genuine

funnily enough the eBay source I bought from is the same listing starcat referenced with the fake images

Maybe the seller was just lazy and use a photo from elsewhere?

yep my dy294 says around 1520V breakdown into an open circuit, so that's good evidence your transistors have a breakdown exceeding that. Also given the markings look correct I would say you have a winner and the price is not crazy low either. (I don't understand why the 294 displays a 1 in the left most column on the 200V range into an open circuit but does not do this on the 1500V range...).

its possible the seller sells a mixture of fakes and non fakes. For example I purchased some 2sk216 and 2sj79 from littlediode on ebay and the sk216s where genuine and the 2sj79s where obviously fake, wrong markings, leads wrong, crazy low breakdown voltage. Returned them. Seller is still selling the same fakes years later.

nikko on ebay also sells fakes. For example their 2SA1968 are fakes. they are not even NPN transistors....

 

 

Edited by jamesmking
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On 6/5/2021 at 1:10 PM, kevin gilmore said:

littlefuse dalbani littlediode nikko...  all the same company. and yes they sell lots of fakes.

2sa1968 are pnp. but if they test as 30v transistors, they are definitely fakes.

Hi Kevin,

I did not realise they where all the same company. 😞

The spec sheet I have (dated 1995 September) says the 2sa1968 are NPN:

image.thumb.png.6fda031a7ad7bcf1b6fc21cfadca29e9.png

However we already have a specsheet which can't even get the pinout right for the G3R450MT17D so who knows anymore...

Every single 2sa1968 they sold me (54 of them) all tested on the peak dca75 as PNP rather than NPN and broke down at around 200V instead of 900V utter junk.

 

Edited by jamesmking
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4 hours ago, Kerry said:

That looks like a bad spec sheet. 

2SAxxx transistors are always PNP and 2SCxxx are NPN

Seriously! OMG how many more bad spec sheets can we find in a week....

ok here's another spec sheet for the 2sa1968 (dated September 1998).. also says NPN...

Untitled.thumb.jpg.4c37bf67e9b9753ac8f43f3373f2ad5f.jpg

Sanyo datasheet (September 1998) also says NPN for the 2sa1967....

Hitachi datasheet (unknown month 1991) for the 2sa1960 says NPN....

looks like many of the 2sa196X sheets are wrong then...

:mikey2:

 

Edited by jamesmking
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  • 3 weeks later...

Hello Folks

Finished the power supply section this weekend. Question from a newbie perspective:  looking for instructions how to adjust/test for the High Bias voltage before installing the new Carbon boards.. R21-50K ?

This is for a Golden Reference LH+LV Version 2.0 

Readings:

Bias H to ground = 436 V

U7 Current regulator pad IXCY10M90S (right of R21) to ground = 650 V

B+ = 418.5 V

B- = -417.6 V

 

 

566505910_IMG_3242(2).jpg.fcb4bf3424daa6a1c19ebc81f7dbe14d.jpg

Thank you

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On 6/7/2021 at 7:20 AM, Blaino said:

G2R1000MT17D GeneSiC Semiconductor | Discrete Semiconductor Products | DigiKey

Will this serve as a sub for the C2M1000170D?  Looks very similarly rated except for power dissipation of 44W instead of 69W.

Looks good. Have you tested it already? 

The G3R450MT17D is a replace as well. It was mentioned somewhere above.

Edited by starcat
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8 hours ago, Sebtdi said:

Hello Folks

Finished the power supply section this weekend. Question from a newbie perspective:  looking for instructions how to adjust/test for the High Bias voltage before installing the new Carbon boards.. R21-50K ?

This is for a Golden Reference LH+LV Version 2.0 

Readings:

Bias H to ground = 436 V

U7 Current regulator pad IXCY10M90S (right of R21) to ground = 650 V

B+ = 418.5 V

B- = -417.6 V

 

 

566505910_IMG_3242(2).jpg.fcb4bf3424daa6a1c19ebc81f7dbe14d.jpg

Thank you

I was able to replace a Zener diode to 100V instead of 130V - now have 580V bias supply

Thanks to Kerry for his assistance!

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On 6/29/2021 at 3:55 AM, Sebtdi said:

I was able to replace a Zener diode to 100V instead of 130V - now have 580V bias supply

Thanks to Kerry for his assistance!

Very nice, congrats!

Are you building the amp and PSU in separate chassis? 
Need moar pics 🙂 

Edited by starcat
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  • 2 months later...
  • 2 weeks later...
10 hours ago, audiostar said:

Sadly, that C2M0045170D isn't available as well...

as I understand C2M1000170D differs from all of them:

Quote
  • High Speed Switching with Low Capacitances
  • Ultra-low Drain-gate capacitance

Yes, C2M1000170D is not so powerfull but those features may be more important.

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16 minutes ago, audiostar said:

I am using the C3M0350120D as a replacement part for the C2M1000170D in the GRHV in my CFA Electrostatic without any issues. But this part seems to be unavailable now as well. Remarkable how one needs to wait a year for parts now.

try Ebay for the 170D this is where I got mine this spring

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