Orange Bass Butler

tuck · Post by **tuck** » 22 Feb 2023, 23:09

You could try to update the firmware first. But don’t blame me if it fails

There is a huge thread over at eevblog for this testers
https://www.eevblog.com/forum/testgear/ ... er-project
Precompiled FW collection
https://disk.yandex.ru/d/yW8xa5NJgUo5z

I updated the T4 with an usb isp which worked well. But this model is easier to deal with. The enclosure of the T1 is better than no enclosure though.

mediy · Post by **mediy** » 23 Feb 2023, 11:43

Quick question about what D5 is. It's not identified in the schematic except as a zener. Is it a 18V zener to regulate the input voltage? Could be protection but I would expect to see a low ohm resistor before it if that was the case.

Tassieviking · Post by **Tassieviking** » 23 Feb 2023, 15:02

Tuck, I got the mono amp module in the 3116D2, it can deliver 100watt.
I got a small 5v fan from Tayda and a 7805 regulator to fit the 125B box.
I might fit a 7809 regulator as well and have a 9v output for my Sunn Beta Pre.
Just search for 3116D2 MONO in Ebay and you should find them.
I have to make a lead up with alligator clips for a car battery for traveling.

Tassieviking · Post by **Tassieviking** » 23 Feb 2023, 15:15

Bajaman: what size are the PCB's you made up for the bass butler ?
I might grab a couple if the width and height are right for my purpose.
That's if you still have some left to sell.
I was going to make my own PCB because I don't like the pots so far down towards the stomp switch.
Today I was working on a PCB with dual gang C20k pots in it and I had to make my own right angle PCB legs for them.
I could do the same on the bass butler to shift the pots closer together, its real easy.
I just stripped a bit of 6mm wire, 7/1.04 I think, and used the copper wire to bend into legs. (C20k dual are hard to find)

Tassieviking · Post by **Tassieviking** » 23 Feb 2023, 16:24

mediy: I can't see any D5 in the Bass Butler, if you mean the diode (D1) that is between the power input and ground then it can be a normal 1N4001, the symbol is not a zener but a schottky diode in the KiCad software.
I would place a resistor between the power in Jack and the PCB to make it a sacrificial resistor in case of a wrong polarity power supply used.
My preferred method is to use a 1N5817 diode along the wire between the power inlet jack and the PCB.
I solder the diode to the power in jack and a wire to the other end of the diode to go to the PCB, cover it in heat-shrink tubing and its finished.

Tuck: I think I have the same component tester as you, or a very close clone, they are great but I wish I had a case for it.
Silicon Chip Magazine in Australia have a great little tester project in this months edition, the article continues next month.
It uses a PIC chip and a small display to show what it tests, and PCB arms as tweezers, and the PCB pattern and program for the chip is free to download if you want to make it yourself. https://siliconchip.com.au/

I would make one but my eyes aren't what they used to be, it would be great if someone made a kit version with a through hole IC instead of the smd chip. Hardly any components for a great tester that can even display a square wave of the signal.

tuck · Post by **tuck** » 23 Feb 2023, 16:33

D5 is the name on the original PCB. I used a 1N5817 as i could not read the original value only 1N...N I didn't want to desolder the diode.

On ebay there are "Clear Acrylic Case Shell Housing for LCR-T4" for mine. Maybe there is one for yours?

bajaman · Post by **bajaman** » 01 Mar 2023, 07:56

IMPORTANT
I am still working on my bass butler build - mostly working well, but still a bit more work to get the compressor working as i would like - a work in progress

However: i have found some mistakes in the schematic for three of the resistor values in the clean section DI out.
According to the Orange part numbers and checking Tuck's resistor photos, R85 should be 2k2 NOT 1k2, R91 and R93 should both be 10k NOT 22k and 1k respectively !
Changing these resistor values makes a HUGE difference to the clean cabsim frequency response

With respect to Tuck's board layout numbers: R67 should be 2k2, and R74 and R76 should both be 10k
As far as i can tell these are the only errors with regards to resistor values
Cheers
bajaman

temol · Post by **temol** » 01 Mar 2023, 10:33

Hi bajaman,

are you using VTL5C3 or your own LDRs?

bajaman · Post by **bajaman** » 01 Mar 2023, 19:53

Hi Temol
I am using these: https://www.aliexpress.com/premium/VTL5 ... 959&dida=y
They use a red led and seem to work fine in most circuits - my problem with the bass butler at the moment, is that I don't seem to be getting enough signal to turn the led on
cheers bajaman

bajaman · Post by **bajaman** » 03 Mar 2023, 04:37

I can now confirm that the compressor section works with the Chinese VTL clones, although it is not a compressor it functions more like a limiter - above a certain input (threshold) level the signal level remains the same despite adding more gain from the compressor control
With respect to the fake J201 through hole devices, I gave up on them and decided to use some through hole 2N5457 devices which tested similar ids as the genuine smd J201 i had in stock - both show ids of around 0.21mA on my TC1 tester - in a practical circuit the 2N5457 has slightly higher gain when biased the same with 43k resistor (approximately 0.75 of the supply voltage on the drain terminal) My advice to anyone wishing to build this pedal: DO NOT USE THE CHEAP CHINESE FAKE J201 ! - use the genuine smd MMBTJ201 from a REFUTABLE supplier such as digikey, mouser, rs components, element 14 etc OR use 2N5457 and select for 0.21mA ids
cheers
bajaman

temol · Post by **temol** » 03 Mar 2023, 13:26

bajaman wrote: I am using these: https://www.aliexpress.com/premium/VTL5 ... 959&dida=y
They use a red led and seem to work fine in most circuits - my problem with the bass butler at the moment, is that I don't seem to be getting enough signal to turn the led on

I recently bought a set of these from Aliexpress. One had a fried LED, luckily you can open the housing and replace it.

bajaman · Post by **bajaman** » 04 Mar 2023, 06:00

yet another update: I tested a few more of the smd MMBFJ201 I had in stock and the 0.21mA Id one i originally tested was on the low end of the scale it seems - after testing four more with my TC1 tester they measured: 1/ 0.36mA Id@243mV Vg
2/ 0.4mA Id@ 280mV Vg
3/ 0.37mA Id@ 257mV Vg
4/ 0.38mV Id@ 268mV Vg
I made up some adapters with perf board and cut off resistor wires and inserted these four MMBFJ201s in the Q2 -Q5 sockets and the response was a lot smoother and better sounding to my ears - the 2N5457 devices worked ok but had a bit too much gain compared to the MMBFJ201 devices and would therefore require extensive modifications to the intermediate 100k/220k dividers to sound as good as them
I did try some selected through hole 2SK117GR devices but they had way too much gain in this circuit - even though they biased up correctly with the 43k drain loads - those potential dividers would have to be modified drastically for these to work properly
Looks like the best option is what Orange took - use ON SEMI MMBFJ201 devices (although the 2N5457 devices come very close second;-) )
I am zoning in on a finished working Bass Butler now: I used some Chinese FAKE TL072 op amps initially and was puzzled by what appeared to be severe crossover distortion and/or parasitic distortion on the bottom half of the signal on my scope. After replacing them with some MC33178 devices (look it up

) the nastiness went away completely - NOTE TO MYSELF: STOP BUYING CHINESE SEMICONDUCTOR DEVICES FROM ALIEXPRESS - they are ALL suspect!!
I ended up using these MC33178 devices for ALL the dual op amps and my power supply was very happy (5532s draw HEAPS OF CURRENT) Everything works as it should now and sounds awesome
cheers
bajaman

bajaman · Post by **bajaman** » 05 Mar 2023, 02:19

I spent some time with the bass butler build and the more i played with it the less i liked the drive section - the clean channel works brilliantly - the compressor works well and the tone controls are smooth acting and overall do exactly what is required, BUT, that drive channel sounds scratchy and thin to my old ears so i decided to do something about it

Earlier in this thread somebody suggested that the drive channel was based on the Orange Rockerverb and yes, it is a four section cascade gain drive channel the same as the Rockerverb BUT, the 3 cathode bypass capacitors in the Rockerverb are nearly 20 times the size of the bass butler drive channel jfet source bypass capacitors ! It appears that the designer wanted to get the classic Marshall brilliant channel response by choosing 2k7 paralleled to 680n for the first gain stage - having such a small bypass capacitor gives a strong presence boost to this first stage and consequently a severely constricted bass response. But if you examine a classic Marshall gain channel you will see that the following gain stages have a much more even frequency gain response, so why did the Orange designer simply repeat the first stage presence boosted jfet stage for the second and third stages ? it beats me why, because it does not sound pleasant - I had to reduce the treble AND midrange controls to zero and still it sounded like fingers scraping down a blackboard to my ears.

Okay - lets take a look at the Rockerverb then - 10uf bypass capacitors on the first three stages ! That is a whole lot bigger than the three 680n capacitors used in the bass butler circuit, and should improve the lack of bass frequencies !
AND - there is a small capacitor across the input gain, and 2nd and 3rd stage drain resistors to tame the high frequency response. Finally there is greater attenuation between the first and second and third and fourth gain stages.
So after performing some modifications i came up with a far nicer sounding gain channel
Here are the Orange Rockerverb partial schematic and my modified bass butler partial schematic
cheers
bajaman

Tassieviking · Post by **Tassieviking** » 05 Mar 2023, 04:13

Great work Bajaman, even if it means I have to change my PCB layout and schematic again.
(Grumbling and moaning with a smile on my face)

tuck · Post by **tuck** » 05 Mar 2023, 12:56

Me too

Thanks Bajaman!

blackboarcult · Post by **blackboarcult** » 05 Mar 2023, 17:12

Threw it all in spice, closer indeed

Measure taken just before the passive tonestack, but after the filtering that follows the last gain stage.
This additional filtering on the Butler makes Baja's more prominent on the low mids than the original rockervb, but given how shrill jfets can be sometimes, it's probably better this way.

bajaman · Post by **bajaman** » 05 Mar 2023, 21:11

Hi - thanks for the analysis blackboarcult

The lower midrange prominence ( the broad peak around 350Hz) can be reduced by leaving the first source bypass capacitor only as 680nF

cheers
bajaman

tuck · Post by **tuck** » 06 Mar 2023, 22:07

Bajaman, I will change the parts on my next build (BB without DI). The standalone drive channel was already soldered and does not sound scratchy to my ears but I will compare it surely.

Tassieviking · Post by **Tassieviking** » 11 Mar 2023, 17:34

Bajaman- where did you find the MC33178 in the Pdip-8 configuration ?
I can only find them in SMD when I look around in Oz.
Also, did you use MLCC caps for C30, C33, C36 so they fit in ok ?
I can see that you changed R57 from 100k to 220k, that's the only resistor I can see that is changed.
I can't wait to give this one a try.

bajaman · Post by **bajaman** » 11 Mar 2023, 23:36

Hi Tassieviking
I bought the MC33178 devices many years ago, but I recently purchased some from Aliexpress and was surprised that they seem to be genuine, in as much as they were just as miserly with their current draw and low noise.
i used MLCC caps throughout except for the large power supply filter capacitors
I changed R43 to 180k as well

The most important changes were the cathode bypass capacitors (I left the first one as 2k7 though) on the second and third stages
cheers
bajaman

Orange Bass Butler [schematic]