Jump to content

The Ultimate DIY Part 2 ? The KGITSOJC


kevin gilmore

Recommended Posts

  • 3 months later...

actually we should rename this thread KGITSOCH

because this input section is virtually the kx-r with a few mods

that make it even lower distortion, lower noise, and faster.

No feedback of any kind.  Should be doing a test run of boards very soon

 

http://gilmore.chem.northwestern.edu/ubaltobal2.jpg

Edited by kevin gilmore
Link to comment
Share on other sites

  • 3 weeks later...

I have tested it, listened to it, works great.

offset is 1.5mv

 

going to swap out the opa445 for op27 and then remove

the offset pots. and probably add a pot on the pnp current

source to do a final trim.

 

input impedance with the bipolars is 10k.

replace them with the jfets and it works better

Link to comment
Share on other sites

  • 3 weeks later...
  • 2 months later...
  • 3 weeks later...
  • 2 weeks later...

Input JFETs just came in the mail. Most of them look real, there are a couple 2sk170s that have funky looking printing on them that I'm not sure about. Will measure IDSS later. 

 

Finally the project can move forward! Actually, I still need to get a few more things. Just ordered the amp and PS cases yesterday, and am about to put in a final mouser order for some other parts. I'm going to be out of town this weekend but should have the attenuator boards and Multi Amp up and running fairly soon, and breadboarding the ubal to bal and phono boards will shortly follow.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

So the poverty version of the KGITSOJC would be the ubal to bal (stuffed with jfets) driving the dynalo boards? And I guess a switch between pre and headphone outs?

 

I'm curious about this dynamic piece of equipment, but Iv'e only got k401s and some random onkyo I found lying around. 

Link to comment
Share on other sites

If you're interested, have the KG or similar digital attenuator boards, and are willing to wait a couple more months (really sorry about that, I'm pretty busy these days and don't have enough time to do much except sleep by the time I get home), I'll hopefully have finished the microprocessor and touchscreen code, and the android app code to implement in the KGITSOCH so you can build the full version. I aim to finish soldering most if not all the amp hardware this weekend but not sure about the next time I'll have some free time. My Nexus 4 should be getting the Lollipop update sometime next week and I think I'm planning on getting the Nexus 6 anyway (verdict still out on whether or not it's too big) so I can use them to test the app.

 

The only dynamic headphones I still have are a couple of vintage orthos.

Link to comment
Share on other sites

i've started working on the 4dsystems 3.2 inch touch lcd again. I think its the right

answer whether you use it standalone, hooked to a arduino, or raspbery pi, beagleboard etc.

 

still looking for an easy solution that combines this display with a wifi enabled web page

controller. (yep i'm lazy)

 

will publish the 4dsystems standalone code when i have time to test it.

Link to comment
Share on other sites

  • 7 months later...
  • 9 months later...
  • 1 month later...
  • 4 years later...
  • 4 months later...
  • 1 year later...

Hi

Could somebody help me out please? I have started building the KGITSOJC, got the boards and the components. What resistor value should I use for resistors labed RF on the silkscreen? For the power supply I'm building GRLV, is it okay to use +/-15V or should I use +/-20V? I have a suitable transformer for 15V output already, but I can get a new one if it is better to use 20V rails.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.