Search found 109 matches

by Lithium_Grim
23 Mar 2024, 14:55
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Dirk_Hendrik wrote: 23 Mar 2024, 14:41 Niet dat het voor de werking iets uitmaakt ;-)
True. i just mentioned it as there will be a notabel difference between a 220R and 10k.
by Lithium_Grim
23 Mar 2024, 14:19
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

I think you made a small mistake in the opamp part of your sketch. It is a 10k in series to a 220nF to ground, not a 220R to ground. I double checked the traces that this part is correct and it is. Kortom, volgens mij moet je de R en C omdraaien die je aan pin 6 van IC1B hebt getekend in je schets. ...
by Lithium_Grim
15 Mar 2024, 18:31
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Ok, here are the first pro measurements of the transformer I can share:

Image
by Lithium_Grim
12 Mar 2024, 07:08
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

I double checked the output wiring. Pin 5 and C11 go directly to the groundplane. I also checked that the groundplane connects all the ground points (it does :)). As for the wiring. I did not measure it but it looked a bit thicker than pickup guage. On request of liquidfunkateer (Alex) I've sent it ...
by Lithium_Grim
03 Mar 2024, 20:56
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Thanks for the good work!! 6,000 H seems impossible, unless the comma is a decimal point, or it’s mh. It would be great if you could measure the frequency response through the transformer if we are looking for a replacement/substitute. I’m guessing it’s a quad-coil 1:1 input transformer from your r...
by Lithium_Grim
01 Mar 2024, 15:31
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

And now some measurements of the transformer with my LCR45: T1 desoldered (LCR45 @ 1kHz) 1-2: 96,3 Ohm DC, L = 1,486H @1kHz Impedance : +5.86k +j9,242k @1kHz Admittance: +48,95u -j77,83uS @1kHz Mag/Phase : 10,88k 58 deg @1kHz 3-4: 144 Ohm DC, L = 1,463H @1kHz Impedance : +5.784k +j9,145k @1kHz Admit...
by Lithium_Grim
27 Feb 2024, 16:03
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

I measured the trasformer with a 10V AC/50Hz source:
Image

Looks like a 1:2 ratio.

I'll be sending off the transformer for further analysis but would anyone recommend any other tests I can do at this moment?
by Lithium_Grim
14 Feb 2024, 19:48
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Thanks. Touchy subject :) My function/signal generator died on me a month ago... RIP. I just ordered a cheap but decent scope/tone generator/multimeter from china, will arrive in a few weeks. good enough for this kind of work.
by Lithium_Grim
14 Feb 2024, 07:01
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

I am currently getting an AC powersupply/variac so I can determine the ratios. 10V on the primairy and i'll determine on both secundairies what the voltage is to find out the ratios. Or am I missing something still?
by Lithium_Grim
13 Feb 2024, 10:26
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

And here is the adjusted schematic.

Image

Anyone see any obvious mistakes or points of further investigation?
by Lithium_Grim
13 Feb 2024, 07:46
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

my guess is that the fet is a BF245A smd equivalent (https://www.onsemi.com/pdf/datasheet/bf245a-d.pdf) The vgs and idss fall into line with this device and it was the jfet used in the classic Urei 1176 studio compressor Thanks bajaman! Since the BJT is a SMD, what equivalent BJT would you suggest?...
by Lithium_Grim
12 Feb 2024, 19:28
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

And some more info on the trannies: https://i.ibb.co/swxy9b0/BJT-info.png https://i.ibb.co/ph4YbkF/BJT-hfe-vs-Ic.png https://i.ibb.co/8NpL8SL/BJT-hfe-vs-Vce.png https://i.ibb.co/JKGd2JG/BJT-Ic-vs-Ib.png https://i.ibb.co/M6wnw4s/BJT-Ic-vs-Vbe.png https://i.ibb.co/gD91KDf/JFET-info.png https://i.ibb.c...
by Lithium_Grim
12 Feb 2024, 18:19
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Ok here is the full version. Still not 100% verified, but I did multiple runs on all traces. https://i.ibb.co/Cb2cb8d/Bogner-Harlow.jpg I am still looking for input on the transistors. The Hfe of the BJT (U2/U3) seems to be higher than the MMBT4401. Any suggestions? I am also still looking for sugge...
by Lithium_Grim
12 Feb 2024, 06:24
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner - Harlow Compressor (gut shots) [traced]

Any ideas on the JFET?

Q1 measured @ DCA75 as N-Ch JFET symmetrical Source/Drain
Vgs[off[=-1,64V @ Id=4,8uA
Vgs[on]=0,32V @ Id=5,00mA
gfs=4,0mA/V@ Id=3,0mA to 5,0mA
Idss=3,67mA @ Vds=3,00V
Rds[on]=270,6 Ohm @ Id=5,0mA and Vgs=0,0V
by Lithium_Grim
11 Feb 2024, 13:44
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner Harlow Compressor [traced]

I received the board from liquidfunkateer (alex) and am tracing it as we speak. Here is a first schematic sketch of the degooped part: <removed due to alterations> In purple the designations as found on the degooped PCB and the now desoldered pcb: https://i.ibb.co/xq6ZXpb/IMG-20240211-162148.jpg Que...
by Lithium_Grim
10 Feb 2024, 21:43
Forum: Boutique Stompboxes dissected...
Topic: Bogner - Harlow Compressor (gut shots) [traced]
Replies: 40
Views: 53438

Re: Bogner Harlow Compressor [traced]

Looking at the trannies on the main board now. They are marked 12x or i2x. Does anyone know what type of trannies those are?

Image