100W Ultimate Fidelity Amplifier

Yes I know. I have some 0R33 coming. The 0R68 seem to be working fine so I'll probably just leave those for now. I plan to build a couple more different versions since I have plenty of boards. I want to try one with NJW3281/1302 outputs. I'm also going to try using just the IPS section for a Slewmaster. Should be interesting. I might even try throwing some MOSFETs on the backend. Fun Stuff!

Hi Juan,

The TO-3s fit fine. No problems.

"The TO-3s fit fine. No problems."

thanks Terry :up: I have another project that I wan to try out too I'm just re-drawing Apex HV23 this can be interesting :):bulb: I never try mosfet amplifiers before
note: don't mind about "CBE" on the TO-92's is going to change later on :D

Regards
Juan
 

Attachments

  • Aoex HV23 re-drawing 2014.jpg
    Aoex HV23 re-drawing 2014.jpg
    365.1 KB · Views: 1,347
Last edited:
Yes I know. I have some 0R33 coming. The 0R68 seem to be working fine so I'll probably just leave those for now. I plan to build a couple more different versions since I have plenty of boards. I want to try one with NJW3281/1302 outputs. I'm also going to try using just the IPS section for a Slewmaster. Should be interesting. I might even try throwing some MOSFETs on the backend. Fun Stuff!

BTW, Terry, have you ever started a thread discussing all this extensive experience you've got from all these builds (X-BoSoZ, B1 Mezmerize, ESP P101, Symasym, KSA 50 X 2 Aleph-X, Leach Low TIM, Leach Superamp, Dx MKIII, DX Super A, Honey Badger, JLH 1969, Gainclone. FetZilla, Peeceebee X2, VSSA PMI, VSSA jkuetemann, SKA GB150, Ovation nx, Slewmonster with; CFA-XH, Wolverine, Spooky, Symasui, Low TIM hybrid)?
 
Last edited:
BTW, Terry, have you ever started a thread discussing all this extensive experience you've got from all these builds (X-BoSoZ, B1 Mezmerize, ESP P101, Symasym, KSA 50 X 2 Aleph-X, Leach Low TIM, Leach Superamp, Dx MKIII, DX Super A, Honey Badger, JLH 1969, Gainclone. FetZilla, Peeceebee X2, VSSA PMI, VSSA jkuetemann, SKA GB150, Ovation nx, Slewmonster with; CFA-XH, Wolverine, Spooky, Symasui, Low TIM hybrid)?
No Sir but I was deep into each of those threads. I'm just a builder/tester. I need help with any technical issues. Had fun building and learned something new with each one. Still have most of them and listen to them as often as I can.

There is some version with mosfets FX14 and NX14 in post #277
http://www.diyaudio.com/forums/solid...ml#post2265286

Thanks Miles,

I just printed out the FX14 schematic. Looks identical to this one except for two resistor changes, delete two diodes and add four zeners to the bottom of the board. And of course, the DMOSFETs. I may start on that one today. :D

Do you guys know if KSC1845/KSA992 be used in place of the BC547/557? I would like to use a pair of these as an IPS in +-70V Slewmaster.

Thanks, Terry
 
OK, so I stuffed the FX-14. Of course I'm still missing the 1n5 capacitors so I will have to wait until the order comes in. Looking forward to hearing it. The Ax-14 sounds pretty good. I did build a small Zobel network on perf-board since these don't have anything on the output. Here are some pics of the FX.

Blessings, Terry
 

Attachments

  • FX14 top.jpg
    FX14 top.jpg
    473.9 KB · Views: 1,253
  • FX14 bottom.jpg
    FX14 bottom.jpg
    468.4 KB · Views: 1,129
  • Zobel.jpg
    Zobel.jpg
    635.4 KB · Views: 1,073
Terry I have the PCB for the protect and coil I made it a few months ago for example binding post of this type on the images, by the way nice coil solution looks great :D

hey about the zener I think I might be able to relocate them to have on top of the board I will see if I can do it either way your way to do it is fine :D

Terry what is the part number of that yellow insulator you are using I have see it a few projects of yours :)

Regards
Juan
 

Attachments

  • Protect zobel and coil.JPG
    Protect zobel and coil.JPG
    559.3 KB · Views: 995
  • binding posts.JPG
    binding posts.JPG
    231.3 KB · Views: 343
...................Do you guys know if KSC1845/KSA992 be used in place of the BC547/557? I would like to use a pair of these as an IPS in +-70V Slewmaster. .............
Yes, but !
different lead out.
the BC5xx are exceptional at very low Vce.
LTP have high Vce and the sa/c can be swapped in with leg re-shaping and a tube of insulation.
Don't use them in mirrors.
 
Yes, but !
different lead out.
the BC5xx are exceptional at very low Vce.
LTP have high Vce and the sa/c can be swapped in with leg re-shaping and a tube of insulation.
Don't use them in mirrors.
Hi AndrewT,
why we can't use it for mirrors ?
I thought we can use any to-92 transistor for mirrors
or what is the best to use in mirrors ?

btw I'm finishing other channels of AX-14,
will have it tested soon :)

Regards
 
Hi AndrewT,
why we can't use it for mirrors ?
I thought we can use any to-92 transistor for mirrors
or what is the best to use in mirrors ?

btw I'm finishing other channels of AX-14,
will have it tested soon :)

Regards

Hi John,

I think AndrewT does not recommend using BC5xx for mirrors mostly because of SOA limitations - BC5xx has got rather low maximum Vce (Vcb). Otherwise they are excellent low noise, high Hfe transistors.

Cheers,
Valery
 
Last edited:
Hi Valery,

Which transistors would you recommend as replacements for the BCxxx devices in this circuit if one wants to go to +-75V rails?

Thanks, Terry

Hi Terry,

Referring to >schematic in post #3305< - you are safe using BC5xx here. All of them are at the places, where Vce is rather low and it will not grow with the rails increase.

Cheers,
Valery
 
Well of course I couldn't wait for the parts so I stacked a bunch of ceramic caps to come up with the 1n5 caps I needed. I'm kind of glad I did. This thing sounds really nice. I have been A/B'ing it against a few amps and it's holding its own pretty well. I will try to find time to hook up the TO-3 version so I can A/B them together. Right now I'm pretty impressed with this MOSFET version.

Blessings, Terry
 

Attachments

  • FX-14 playing.jpg
    FX-14 playing.jpg
    553.8 KB · Views: 777
  • MOSFET playing.jpg
    MOSFET playing.jpg
    551.4 KB · Views: 756
I'm really happy that you got work it with mosfet version a amazing :D how is the sound ?

I was about to modified the AX-14T layout but I think is not necessary as you did it under the PCB is not going to be seen any way :p, about other things I was working on the Apex HV23 a high power version I just re-drawing it and looks good I have to check if all to make sure is correct maybe later I will order some :), and yes good idea to have the mosfet and the regular in the same chassis that is interesting looking good man :)

Regards
Juan
 

Attachments

  • Apex HV 23 bottom.png
    Apex HV 23 bottom.png
    874.9 KB · Views: 827
  • Apex HV 23 1.jpg
    Apex HV 23 1.jpg
    395.1 KB · Views: 781
Last edited: