Spooky and Hellraiser SMD 60W amps (wolverine compatible IPS)

[chat72]

For pnp vbe=-48mv npn vbe=-53mv why I get both negative??

 

[jwilhelm]

None of them are getting enough voltage to switch on. The NPNs should be showing positive voltage though. What are your base to emitter voltages on Q105, Q106, Q107 & Q108?

 

[chat72]

Vbe for q105 107 is -0.59v. for q106 108 is 0.59v.

 

[jwilhelm]

Can you post the build files you are using? I think the jumper wire connections are wrong on the one I'm looking at, but it doesn't match the boards you have. This might be what Wowan was referring to.

You can verify this with your ohm meter. The emitter of Q107 should connect to R114 and R115. The emitter of Q108 should connect to R116 and R117.

 

[chat72]

I can see that now, j1 and j2 are wrong ( there is no jumper in scheamatic). I need to cross it. The picture show wrong connection.
My pcb is an early version I did not aware of this issue.

 

[chat72]

I cross j1 and j2 and it is wotking now, thank you all. It seem that there is no harm done to all trs.

 

[jwilhelm]

Good to hear you have it working.

The latest version of the mini in post 1 still has this same issue.

 

[bullittstang]

It appears V1.2 has fixed this, there are traces from top of R111/C112 to E of Q107, and a trace running from bottom of R111/C112 to E of Q108.

 

[ostripper]

Pd-nd= 4.75v

that should give about 120mA @ across Re.

 

[ostripper]

there is something wrong ?
I'll fix it !

 

[ostripper]

It looks like V1.2 is the fix.

 

[ostripper]

I need to fix it. SHAME !!!!
1.3 is about done.

 

[chat72]

They are singing now. Infidel!!

 

[ostripper]

Sorry you had to fix (J1/2). I fixed the mini V1.2 '"package". Are you using Rtmc or 2 pole comp. (R18) ?
OS

 

[chat72]

I am using R18 and there is an error on infidel ips R21 should be 22K and R22 should be 820E.

 

[ostripper]

I am using R18 and there is an error on infidel ips R21 should be 22K and R22 should be 820E.

Schema's right ... PCB silkscreen error ??

 

[chat72]

It's silk screen error. I will give detail of my built later.

 

[ostripper]

Yes... I notice you are using .33R/5W , that should be even more stable thermally. It looks like you could not find SMD trimmers, either.
I'm glad it "sings"...
PS - BTW , the Infidel is a Wolverine (with a cascode and led biasing). Unlike the Wolverine , the led's actually do something and this VAS
soft clips on overload. Simpler , as well. Should come close ... (3-5PPM).
OS

 

[chat72]

Here is my build, OPS is mini ef3 version 1.1. Schematic value except re=0E33 and output vbe is ksc2690. There is one issue with this board, you must cross between j1 and j2 see picture below.

IPS is infidel v1.0 all value follow schematic with one issue on silkscreen, at r21 use 22k and at r22 use 820E, see picture below.

Offset is rock-solid stay at almost 0mv. I have a bit of problem with mje340 as an output vbe, bias jump up sometime, change to ksc2690 solved that.
VAS current is set by dial r14. I have v=1.2v across r14//r15. I set r14 so that r14//r15 is around 320E.

SMD trimmer is expensive compare to chinese made trimmer, it’s on ips so you can easily change it later.

 

[chat72]

Just for fun, HH-simple IPS, all THT Semi, mini MELF=1206 SMD resistors +THT parts only 5cmx5cm board.