WOW! Very Impressive stuff here!!

[Yazoo]

I know i'm getting obsessive again. The Engl uses 3 TRS switches which I haven't been able to source, even from Mouser. Anybody know any suppliers for these? They are made by TTI and the part number is TRR2A12D.

[KMG]

How do you do the power supply for that please? I saw the board needs 200V. What is the amperage requirement and do you have a layout available for the power supply?

All files there
http://milas.spb.ru/~kmg/files/projects/200vdcdc/

The Engl uses 3 TRS switches which I haven't been able to source, even from Mouser. Anybody know any suppliers for these? They are made by TTI and the part number is TRR2A12D.

Exact type TRS-12VDC-SB-L15
http://www.tai-shing.com.tw/images/prod/relay/relay-trs_spec.pdf
There are many manufacturers made same types of relays
Axicom Relays
http://www.te.com/catalog/bin/TE.Connect?C=16656&M=PPROP&P=91219,78007,88861,112360&BML=18028,21253&LG=1&PG=1&IDS=113465,121033,113466,175907,110040&N=1
hongfa
http://www.hongfa.com/pro/HFD2_en.html
Simply search for DPDT(2C contacts type) telecom relays & check for same parameters & pinout.

[Yazoo]

Thanks for the information. I've only ever built stomp boxes before so a lot of this is new to me. I now understand your power supply design is an SMPS which boosts the input power up to 200 volts. What kind of AC transformer do you need to feed this?

[KMG]

What kind of AC transformer do you need to feed this?

About 14VAC x 0.5A

[Yazoo]

I am building up a parts list for the Engl FET pre-amp and power supply. The power inductors on the power supply are proving hard to source. The parts listed are manufactured by Sumida but I have not been able to find a supplier in the UK which stocks these. The first is RCH110NP -101K, 100 microHenrys with a DCR of 0.16 Ohms, rated current of 1.7 amps and SRF of 5.7 MHz. The second is RCH110NP-102K,  1 mH, DCR of 1.7 Ohms, rated current of 0.53 amps and SRF of 1.7 MHz. Does anybody know of a UK supplier who has these or an equivalent.

Again, thanks for everybody's patience - I know I'm being a pest.

[Yazoo]

I think I've found suitable inductors made by Panasonic, the 1 mH one rated at 1 Ohm DCR and 0.5 amps, and the 100 uH rated at 0.16 Ohms and 1.7 amps.

I've etched and drilled the pcbs for the power supply and the main pcb. My only query now is about tuning the transistors as mentioned on KMG's website "With proper assembly, tuning is reduced to the adjustment of the drain voltage of transistors in accordance with the schematic by trimmer resistors." What drain voltage should I be aiming for?

[KMG]

Set 134V at Q2 drain by rotating PT1,  134V at Q5 drain by PT2, 113V at Q8 drain by PT3, 138V at Q11 drain by PT4.

[Yazoo]

Great! Thanks for the information.

[AudioEcstasy]

Great site thanks for sharing! 

[KMG]

Mini head project - LND150 based JCM800 preamp + 5W FET PA.

[Yazoo]

WOW!

I'm about two thirds the way through building the ENGL but it's never going to look as good as this.

[KMG]

It's not real device yet, just rendering from SolidWorks.

[Yazoo]

I'm using an old 1U rack to house the Engl. I've filled in the holes on the front panel with epoxy resign glue and spray painted it black but it doesn't match the professional look of your builds.

[KMG]

Library of presets for V1000/AL3201 hacked from XENYX1202FX mixer console (100 effects).
Archive contains object files, disassembled source codes & effects list pdf file.
http://milas.spb.ru/~kmg/files/projects/dre/xenyx1202fx.zip

[J0K3RX]

KMG

Just ***AMAZING*** work man!!! I idolize you! 

***AMAZING******AMAZING******AMAZING***

[Yazoo]

I have built the ENGL 530 preamp and I'm at the debugging stage. The drive channel is working but I am not getting anything out of the clean channel. Before I start checking the board for any mistakes I have made could I just check how the footswitches work please? I decided not to use a led indicator so I replaced the DPDT footswitches with a couple of SPDT panel switches. From the pictures it looks like one side of the DPDT switches is used to switch the LEDs off and on and the other side switches the TRS switches by connecting them to ground.Is that correct?

[KMG]

Modes:
Clean: J4.3-NC, J4.4-NC/GND(J4.1) does not matter in clean mode.
Crunch: J4.3-GND(J4.1), J4.4-NC
Lead: J4.3-GND(J4.1), J4.4-GND(J4.1)
So, J4.3 controls switching from Clean to drive modes, J4.4 switch between Crunch/Lead modes in drive mode.

[Yazoo]

Thanks again. I tracked the problem down - you've got to laugh. I used 0000 grade wire wool to clean the board and when I finished putting it together, I painted the copper tracks with clear nail varnish. I've spent the last three nights tracing through the board with an oscilloscope and a signal generator and found that immediately before the last transistor, the signal was grounding on the clean channel. When I checked the board today there was a single filament of wire wool short circuiting to ground!

It's all working now and here is a picture of my effort housed in a recycled 1U rack.


May I ask one last question please? When you use the E-MU tracker before the ENGL, are you boosting the signal before it gets to the ENGL and if you are, roughly how many dbs are you doing this by?

[KMG]

May I ask one last question please? When you use the E-MU tracker before the ENGL, are you boosting the signal before it gets to the ENGL and if you are, roughly how many dbs are you doing this by?

While recording reamps I used direct cable from E-MU tracker line out to preamp input.

It's all working now and here is a picture of my effort housed in a recycled 1U rack.

Looks good, needs only paintings on front panel.
For my designs I use thin decorative panels ordered in this company:
http://translate.google.com/translate?hl=en&sl=ru&tl=en&u=http%3A%2F%2Fm-graf.ru%2F
I think you can find similar company in your country.

PS what can you say about sound of this preamp?

[Yazoo]

It's good but I think I still have a problem with my build. I am not getting much volume. I've tried it through the V30 speaker simulator and through a Marshall 20/20 power amp but I have to turn everything right up to maximum volume. The chips I ordered were the 2SK216s but I received Hitachi 216 chips. I hope these are fully compatible. Do you have any output readings from the transistors and from the output on the amp so I can check please?