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A Swedish 2SK1058 SE-amplifier
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=5487
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Author:  Soundbrigade [ 21 Feb 2016, 03:29 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

The tube looks a lot like the ones used in Oatleys stuff but I expect it to be much more useful and at least lack the awful microphonics the lowww-voltage tube have.
Now I happen to find this schematic and decided to try it out. This is not supposed to be a premium amp, others in my collection are intended to be, but sometimes, fiddling around, trying new ideas is as good as using original WE 300B.

Author:  mwhouston [ 21 Feb 2016, 17:32 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

Very similar to the Jan6418.

Author:  Soundbrigade [ 05 Mar 2016, 08:16 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

So what am I up to?
Right now preparing a megacarbonated, sugarized brownie with chocolate and peanutbutter topping ...

Else I am waiting for the small tubes, mentioned above and some few components I will use too. The potentiometers for setting bias will be changed for multiturn trimmers. Else, the box is pretty full and I need to some serious surgery to fit all in. One idea is to drill large holes where the leads should go to the FETs and sort of use the holes to fit the boards, that may have to be cut in smaller pieces. I'll fix that .... :wizard:

Attachment:
2SK1058_08.jpg

Author:  mwhouston [ 05 Mar 2016, 19:46 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

Can't wait to hear what you think of the sound.

Author:  Soundbrigade [ 06 Mar 2016, 04:17 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

I had them working just as I had them assembled, but I used a pair of simple home-made computer speakers. However it all sounded, as far as I could judge pretty nice but missed some punch. From a Swedish guy I was suggested to add another FET to make a FETlington-transistor in order to increase gain, but I will try the tube driver. :nuke:

I hope to have all things to finish the project within a week or two. :)

To anyone living in Europe, I have ordered stuff from Reichelt - www.reichelt.com. Very much like Mouser or Farnell, but I like them Reichelt better. Maybe because they are up to the well know German Ordnung und Rednung. :up:

Author:  Soundbrigade [ 26 Mar 2016, 13:49 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

Finally got the tubes, have six of them and a new quartett of transistors. I also bought a wooden storage box (LINK) that has gotten a metal interior to reinforce, especially the bottom. It is spacier than the green box , though not very "electronic"', but I think it will serve its purpose well.
Still waiting for the transformer for the tubes but I think it will arrive next week.

Author:  KrammeAcoustics [ 27 Feb 2017, 11:51 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

hi magnus

well, i guess i missed this thread ( last year was a bitch to me )

so what about the china fake-crap-stuff ( genuine as they call it ) 2sk1058, was the pinout wrong as i warned you about ?

genuine = (g)(s)(d) vs. (g)(d)(s) = fake

when this is said, the wrong pinout fake mosfets actually works, but not as a genuine 2sk1058. an example for the genuine type the vgs is around 1 v ( measurements ). for the fake one vgs is around 4 v ( measurements ).

Image

Soundbrigade wrote:
I cannot remember why I got the incredible idiotic idea to start this project. I guess some small influences from here and there sort of inspired me to get on with it. There were some discussions with another member of the forum about the transistors and some checking on the web the main component, the transistor seemed to be available. A bigger concern was the resistors. How to fins a 15 Ohm/50W resistor?!

To make a long story short, I ordered transistors "real Renesa" on eBay and ended up with crap, but I had understood that would be the case as I waited for the shipment. I also ordered some from a reliable source in Germany and they did work. As I need a few components for another project I will propably be back for some more, just in case ...

OK, back to the project. With all components in place (minus the proposed choke) I could finally start trying the proposed design. Mounted (a working) transistor on a heatsink, Passive components soldered on a small breadboards (the Chinese cannot fake those ...).
I got a special made transformer (2x18V) cheaply from England (eBay), have som 10.000uF and rectifiers suitable for the job, but no appropriate chassis.

A quick setup gave good results immediately. There were no instructions how to set up the amplifier, but I guessed setting the pot in mid position would be fine for a start. Double and triple checked all connections; I managed to kill four Russian power tubes in ten minutes once, so I have learned the lesson, and learned it good.

Before showing to blurry photos taken by my semi-pro mirrorless Canon camera, a few notes. All components are according to original drawings, apart from the plastic caps across the output electrolytics. I could only dig up a pair of 2,2u, and I used 47uF caps on the bias voltage. The PSU isn't assembled as I feel I need a box to put everything in so I powered the amp by my PSU.

Here comes the pictures, as the project goes on I will send more details.

This is the experimental setup. Input grounded, PSU running at approx 24V and DMM across drain and source. All lokks perefctly well.
Attachment:
2SK1059_02.jpg


Now I have attached a potentiometer to the input, connected a speaker and my iPod and play some good music. Not that very loud but that may depend on the speakers.
Attachment:
2SK1059_01.jpg


I also want to thank KrammeAcoustics for good advices and help along the road, that was, actually really short. I have never managed to go from project start to a working device this quick. :eek:

Author:  Geek [ 27 Feb 2017, 14:39 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

I had to get some of those for a Halfler P1500 I was repairing.... that was one time I skipped eBay and AliExpress and went straight to Renesas. Payed through the nose, but it works! :D

Author:  Soundbrigade [ 28 Feb 2017, 04:03 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

I am in Marrakech at the moment ...

The fake ones were fake ones (F**K, I hate the nasty habit of mu iPad to change every second Word I am writing).but the (now) 8 I got from Reichelt were all genuine.

But I have to put everything together ....

Author:  KrammeAcoustics [ 28 Feb 2017, 05:23 ]
Post subject:  Re: A Swedish 2SK1058 SE-amplifier

Geek wrote:
I had to get some of those for a Halfler P1500 I was repairing.... that was one time I skipped eBay and AliExpress and went straight to Renesas. Payed through the nose, but it works! :D


yep, but it's worth paying to get the genuine k1058's. so had you ever purchased some fakes ...with wrong pinout ? or did you learn by hearing about the fake ones ?

Soundbrigade wrote:
I am in Marrakech at the moment ...

The fake ones were fake ones (F**K, I hate the nasty habit of mu iPad to change every second Word I am writing).but the (now) 8 I got from Reichelt were all genuine.

But I have to put everything together ....


bra, stänga mobilen och ipad , du er på semester magnus :beerchug:

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