kgst

[chiguy]

Having a hot air gun / rework station has helped me desolder a lot of things.  I haven't tried a teflon tube socket before but my general procedure is to desolder as much as possible with a desoldering pump and desoldering wick and use the hot air to free it.  I saw a video of a guy desoldering a DVI connector before with a blow torch.  While cringe worthy, it worked.  

[Pars]

Good question, probably not. Pieces of crap I just bought for this. I'll get the Neutrik. Edit: This one I guess

 

http://www.mouser.com/ProductDetail/Neutrik/NA2MPMF/?qs=sGAEpiMZZMv0W4pxf2HiV9y0EyfHsAgRVcOPr0CUs0o%3d

 

 

Damn this amp has a lot of bass control. Scary. Just listening with my test headphones (207) for a few days at least. I'll try a 404 next, my go-to headphone at the moment. It's a warmer amp than the 323S too I believe, but it might be the 207's that I haven't heard in a while. There's some muddy too which is the 207's, need to try some better headphones soon. 

Yeah, those. From the Neutrik description:

 

Wired according to IEC 268-12:

Pin 2: signal

Pin 1 and 3: connected to ground

[charlo89]

Hi,

I am doing my cart on mouser for a KGST Version 0.41 (from the GB last years)

I have issues on some components. (sorry it's noob questions)

 

- For heatsink, I would like to know if this heatsink are good for the 10M90s (Amp) and FQPF8N80C 

                                  http://ca.mouser.com/ProductDetail/Ohmite/FA-T220-64E/?qs=sGAEpiMZZMttgyDkZ5WiumlCfl50RTwzVA%252bY4U4BtvA%3d

and for 10M90s (PSU) 

                                  http://ca.mouser.com/ProductDetail/Aavid-Thermalloy/581002B02500G/?qs=sGAEpiMZZMttgyDkZ5Wiuua5pzU5xE5ZX3Yy1QskXag%3d

 

 

-What insulation kit used for heatsink ?

 

-Where can I buy the transfo for US voltage ?

 

-For the amp I don't find 2 components: the MPSW56 / 2SA970 and the LSK389 / 2* K170 someone can tell me where can I find them ?

 

-For spacers, this one are ok ? 

                                http://ca.mouser.com/ProductDetail/Harwin/R30-3001202/?qs=sGAEpiMZZMtrde5aJd3qw4L16p8RLiBxUh1nBIGYFog%3d

 

-For the terminal block, this one are ok (same series for 3 and 4 inputs/outputs)

                               http://ca.mouser.com/ProductDetail/Phoenix-Contact/1729128/?qs=%2fha2pyFaduimI14tJFhHTXWk%252birF91EiRKtI%2fgMnW8I%3d

 

 

Thank you

Edited April 1, 2015 by charlo89

[xianghao]

Hi,

I am doing my cart on mouser for a KGST Version 0.41 (from the GB last years)

I have issues on some components. (sorry it's noob questions)

.....................................................

 

About the MPSW56:

 

MPSA56 can also work well.

 

here is the link:

 

http://www.mouser.com/ProductDetail/Central-Semiconductor/MPSA56/?qs=sGAEpiMZZMshyDBzk1%2FWixvMFai5%2FBmADuf7Sjp%252bvdc%3D

[chiguy]

Most of your questions are already answered in earlier posts.  This is the info I have readily accessible.

 

Heatsinks:

I used these heatsinks and parts with non conductive thermal grease.

 

http://www.mouser.com/Search/ProductDetail.aspx?R=530002B02500Gvirtualkey53210000virtualkey532-530002B02500G

http://www.mouser.com/Search/ProductDetail.aspx?R=581002B02500Gvirtualkey53210000virtualkey532-581002B02500G

http://www.mouser.com/Search/ProductDetail.aspx?R=4170Gvirtualkey53210000virtualkey532-4170

http://www.mouser.com/Search/ProductDetail.aspx?R=7721-3PPSGvirtualkey53210000virtualkey532-7721-3PPS

http://www.mouser.com/Search/ProductDetail.aspx?R=4880Gvirtualkey53210000virtualkey532-4880 (probably more cost effective to just buy the screws, nuts, and washers in bulk)

 

There are lots of transformer recommendations mentioned earlier in this thread.  There are some from Antek and you can get one custom made.  I got one custom made.

 

LSK389

 

Spacers and standoffs will depend on your build.  

 

I used the same terminal blocks

[charlo89]

Thank you xianghao and chiguy , I found all the components.

I will order everything tomorrow.

[JoaMat]

Fired up! Sounds good, reeeeeeeeeel good. 

 

Great, well done. Next amp in sequence?

Edited November 11, 2015 by JoaMat

[Earspeakers]

Thank you xianghao and chiguy , I found all the components.

I will order everything tomorrow.

 

Which resistors are you using, the Vishay brown 600V versions I hope? 

 

Share your BOM, I'd like a decent KGST BOM for once and I've got another to build. 

[Earspeakers]

Great, well done. Next amp in sequence?

 

Thanks, KGSSHV this weekend. I have everything except (surely) some parts, so have Mouser on 24 hour emergency team notice to dispatch me what I need right away. The KGST was a first get my feet wet. Made a few mistakes with the chassis I'll do better with the KGSSHV. Anyhow expect that in three or four weeks. 

 

After that, the Megatron (if my Teflon caps come in on time), then ... the T2! After that, a BHSE on order that I'm wondering why I ordered, and then I won't know what to do afterwards. Probably a FrankCooter 845 Stax amp. 

 

Oh yeah, here's my handiwork. I call it

 

The Ham

 

 

Because it has a Hammond Chassis and HAM radio parts. Having worked in measurement labs my whole life I like the industrial cold war instrument chassis look. These Hammond Chassis - while Hammond quality and finish (both good enough for my book) - are a treat to work with. I like an easy build and lots of ventilation, these have both in spades. I also have access to a machine shop but prefer just doing some drilling in my garage. I'm going to flesh these out with some dials probably (VU) and a few more knobs and lamps. 

 

I should add, the metal work was simple. Bought a circuit plate in .125 aluminum from OnlineMetals, cut to my specification. Drilled that out with a row of big ventilation holes (hard to see - horizontal under the amp boards) and all the other necessary holes. Attached to the chassis via four 2" standoffs, simply reusing the ventilation holes on the bottom to attach. Then mount all the hardware via standoffs as seen, with the toroid transformer suspended underneath the power supply board. So all the AC is under the circuit plate, and all signal is above.

 

Then it was just drilling out the back plate for XLR and power, and the front panel, both of which were included. If you want to go with FrontPanelExpress obviously you can easily have whatever you want made. 

Edited April 1, 2015 by Earspeakers

[Earspeakers]

Yeah, those. From the Neutrik description:

 

Wired according to IEC 268-12:

Pin 2: signal

Pin 1 and 3: connected to ground

 

Checked the Hosa - yeah 1 and 3 are on ground. Don't know, but the stupid thing hums. 

 

On the KGST - further listening. Truly a beautiful little amp. Information retrieval is remarkable, I heard a Bach Cantata on period instruments, there's a trumpet back there! Poor guy must have been shy trying to play this period piece, but he was buried in the orchestra. Now I'm hearing him. And the presentation is overall warm, inviting and relaxed, but not overly so. 

 

However, the bass sounds uncalibrated to my ears (so far). Too much, and a bit more indistinct than it should be maybe. I need to listen to this with the 007/009 and 4070 to make sure, but cellos and basses are too bassy. Too big, too round, too powerful. Or it could just be me. 

Edited April 1, 2015 by Earspeakers

[DefQon]

I don't think Frankcooter has ever released the schematics to his 845 tube amp.

 

I know the Stax mafia have an 845 tube amp in the works to be released anytime in the not so distant future and few other designs. 

[Earspeakers]

I don't think Frankcooter has ever released the schematics to his 845 tube amp.

 

I know the Stax mafia have an 845 tube amp in the works to be released anytime in the not so distant future and few other designs. 

 

I tried to tempt Birgir into doing a doing a SOTA low end amp. One board, wall wart powered, current parts, like a high end 252S. He was like "I see no reason to do that", lol ... except I'd have a good amp at work. If I wasn't so busy building I'd try my hand at it. 

 

Anyhow interested in their future offerings of course. 

[charlo89]

Which resistors are you using, the Vishay brown 600V versions I hope? 

 

Share your BOM, I'd like a decent KGST BOM for once and I've got another to build. 

 

I put the RN60D series in the BOM

 

It would be great if you could check my BOM.

https://docs.google.com/spreadsheets/d/1O_Csik6CNJkDSBpxWzZmfD5erVDhU7t6aH80WJNWG-U/pubhtml

 

thanks

[chiguy]

I put the RN60D series in the BOM

 

It would be great if you could check my BOM.

https://docs.google.com/spreadsheets/d/1O_Csik6CNJkDSBpxWzZmfD5erVDhU7t6aH80WJNWG-U/pubhtml

 

thanks

 

 

You need 6-32 peek screws for http://www.mouser.com/ProductDetail/Aavid-Thermalloy/581002B02500G/?qs=i82%252bPC3tdLOGMQaV7dyniA%3D%3D

 

Also use 

http://www.mouser.com/Search/ProductDetail.aspx?R=7721-3PPSGvirtualkey53210000virtualkey532-7721-3PPS

http://www.mouser.com/Search/ProductDetail.aspx?R=4170Gvirtualkey53210000virtualkey532-4170

 

for TO-220 devices with exposed tabs.  

[charlo89]

You need 6-32 peek screws for http://www.mouser.com/ProductDetail/Aavid-Thermalloy/581002B02500G/?qs=i82%252bPC3tdLOGMQaV7dyniA%3D%3D

 

Also use 

http://www.mouser.com/Search/ProductDetail.aspx?R=7721-3PPSGvirtualkey53210000virtualkey532-7721-3PPS

http://www.mouser.com/Search/ProductDetail.aspx?R=4170Gvirtualkey53210000virtualkey532-4170

 

for TO-220 devices with exposed tabs.  

 

Thank you

Do you know where can I find  the 6-32 peek screws ?

[Earspeakers]

I put the RN60D series in the BOM

 

It would be great if you could check my BOM.

https://docs.google.com/spreadsheets/d/1O_Csik6CNJkDSBpxWzZmfD5erVDhU7t6aH80WJNWG-U/pubhtml

 

thanks

 

getting an error trying to access that

[chiguy]

Thank you

Do you know where can I find  the 6-32 peek screws ?

http://www.mcmaster.com/

[Laowei]

http://www.solidspot.com/peek_screws.html

 

Best prices that I have found online. I have bought from them, good quality made in Japan product. Good people here in the US  to deal with. Note: Per 100 unit quanities, Imperial is considerably more costly than Metric. Metric are offered in lesser quantities too, saving even more.

[Earspeakers]

I need some more Peek screws and so would split an order with anybody. I have the ones Laowei links to above and they're great. 

Edited April 2, 2015 by Earspeakers

[lkong]

I need some more Peek screws and so would split an order with anybody. I have the ones Laowei links to above and they're great. 

I am interested. Can you pm me some details?

Thanks

[Laowei]

The PEEK screws work great in my KGST running at a low measured 9mA plate load per tube. I would be cautious in using them in a higher stressed area. For the M4 and 6-32 size the rated assembly torque ~2.5 inch lbs. which is half the yield torque of ~5 inch lbs.

For best thermal coupling, you should use stainless steel screws with isolators (and thermal grease) torqued to 10-12 inch lbs.

[Earspeakers]

The PEEK screws work great in my KGST running at a low measured 9mA plate load per tube. I would be cautious in using them in a higher stressed area. For the M4 and 6-32 size the rated assembly torque ~2.5 inch lbs. which is half the yield torque of ~5 inch lbs.

For best thermal coupling, you should use stainless steel screws with isolators (and thermal grease) torqued to 10-12 inch lbs.

 

Do you have a mouser link for the isolators from one of your past orders? I got some here on somebodies advice, and measured with my caliper and they seemed correct, but don't work. 

[Laowei]

You don't want to use the isolators that I first ordered. They were wrong, I modified the heatsinks and smoked a CCS.

Back in this thread there is lots of talk about isolators. No tme for me to search ATM, got to run for the factory shuttle.

[Earspeakers]

Yeah I think that discussion is the one the pointed me towards the wrong isolators. 

[mwl168]

If by isolator you mean the shoulder washer, you want to use 7721-10PPSG. The bushing is 2.41mm which is long enough to extend through the tab of the transistor and some. 7721-3PPSG bushing is 3.81mm but the bushing's outer diameter is slightly larger. In my case, it would not fit through the tab hole of the transistor unless you file and enlarge the tab hole.

The ceramic insulator is either AAVID 4170G or 4171G. Both should work fine. 4171G is thicker but smaller in dimension.

I use 10PPSG with 4171G and the combination works well. Although I may have used 3PPSG if I had the proper file to slightly enlarge the tab hole of the transistors.

Hope this helps.