Complex Amp Footswitch Question

alexreinhold

Senior Member
Messages
656
As @TBurst Std knows, I have gone mostly digital. But lately, I've made it hobby optimizing my beloved amp.

Situation: I have recently bought the Boss ES-5 Switcher/Looper as per @stratamania's advice (see other thread). The device has an amazing functionality to control an amp's channels which I'd love to utilize:

Here are the Boss ES-5 inputs to control amp channels:
1704630886168.png

Problem:
For almost 20 years, I have had a truly wonderful amp called Steavens Poundcake. More info HERE. The amp has 4 channels: Clean, Crunch, Meat (Gain), Heat (High Gain). The switch looks like so:
1704631299319.png
However, rather than being connected via a standard TRS cable, it comes in this weird format (which I haven't seen elsewhere; it's NOT MIDI):
Cable:
1704631384251.png
Input:
1704631456949.png

On the amp's back, I have the following:
This (no pic):
- SLO BLO "knobs"
- Pentode/Triode Switch
- Ohm (4/8/16) switch)
- Speaker Inputs
And this (pic below):
- Right: Line out incl. Level select
- Middle: Effects Loop
- Left: switches (see below)
1704631670824.png

Now I have two inputs for switches on the very left that look like this (please note that on the front of the amp, there are two binary switches called Sect and Mode and I have never understood what they do):
1704632003312.png

Can anyone help me figure out if I can use the Boss ES-5 somehow to switch channels.
1) If yes, how?
2) if no, would there be a way to mod the amp?

Thanks a lot!
Alex

PS: Here's the amp from the front:
1704631193967.png
 
It looks like the 4 channels
-4 channels (Clean/Crunch/Meat/Heat)

As an educated guess, these are possibly two different modes (MODE) of two different preamp sections (SECT) giving a pseudo four channels.

I would suggest then unplugging the cable from the supplied foot switch

You also have Sect and Mode switches on the front of the amp, what do those do?

Once you have figured that out, then using TRS from the ES5 and seeing how using the relays changes things on the amp. You will have to experiment.

One position of the TRS on the right would appear to turn the FX loop on and off.

If you can find a manual, it would help as well.

But MEAT and HEAT, what who thought of those names :D
 
If it were me I'd :
1 - Grab the schematic for the amp and (assuming I knew how the boss switcher worked) design a special cable that linked into the DIN jack on the back of the amp to the boss switcher.
2 - If the schematic was not available, then I'd take apart the footswitch, figure out how it worked, and reverse engineer something from that.

I would not mod the amp.
 
BTW, just a guess from looking at the front of the amp, the TRS jack on the left actually controls the "sect" and "mode" min-switches that are on the front of the amp. Based on that, I think they don't control the channel switching.

BTW, I had a look and could not find a schematic for the amp. Based on that, your best bet is to reverse engineer the footswitch and come up with something from that.
 
 
In the above review, they do mention midi FYI

Yes MIDI out, but in the pictures there does not seem to be any MIDI.

BTW, just a guess from looking at the front of the amp, the TRS jack on the left actually controls the "sect" and "mode" min-switches that are on the front of the amp. Based on that, I think they don't control the channel switching.

Looking at the pictures again, the TRS may not be amp channel related but MODE and possibly SECT may be related to the FX loop where Mode is either a Series loop and a parallel loop setting mixing in some dry signal with whatever is in the loop. A parallel loop setting you would need kill dry in a delay for example to avoid artefacts.

The ES5 has two TRS relays for amp channel switching. The only difference really to a standard TRS foot switch is that the relays are programmable along with other preset settings.

I also would not mod the amp.

If it were me I'd :
1 - Grab the schematic for the amp and (assuming I knew how the boss switcher worked) design a special cable that linked into the DIN jack on the back of the amp to the boss switcher.

That is a good idea.
@alexreinhold perhaps ask an amp tech to help reverse engineer the amps footswitch, probably a little costly to send it to Canada and the good Mr @mayfly to look at.

Perhaps some photos of the internals of the foot switch might reveal something, but this sort of thing remotely is not really the best way to do this.
 
I had a feeling it wouldn't be trivial. I will try what @stratamania suggested and if nothing works (which I assume because I don't think Sect and Mode will do anything about the channels), I will go to an amp repair guy and see if he can create the cable @mayfly suggested.

In the review @Spud posted, they are wrong about MIDI. It's DIN.
 
Yes MIDI out, but in the pictures there does not seem to be any MIDI.



Looking at the pictures again, the TRS may not be amp channel related but MODE and possibly SECT may be related to the FX loop where Mode is either a Series loop and a parallel loop setting mixing in some dry signal with whatever is in the loop. A parallel loop setting you would need kill dry in a delay for example to avoid artefacts.

The ES5 has two TRS relays for amp channel switching. The only difference really to a standard TRS foot switch is that the relays are programmable along with other preset settings.

I also would not mod the amp.



That is a good idea.
@alexreinhold perhaps ask an amp tech to help reverse engineer the amps footswitch, probably a little costly to send it to Canada and the good Mr @mayfly to look at.

Perhaps some photos of the internals of the foot switch might reveal something, but this sort of thing remotely is not really the best way to do this.
I was thinking exactly what you suggest at the end. Let me think about it a bit... I will come back soon.
 
I had a feeling it wouldn't be trivial. I will try what @stratamania suggested and if nothing works (which I assume because I don't think Sect and Mode will do anything about the channels), I will go to an amp repair guy and see if he can create the cable @mayfly suggested.

In the review @Spud posted, they are wrong about MIDI. It's DIN.
Have I mentioned that I once wired a new plug on the end of an extension cord?
 
Alright, there's an update to my endeavor.
The bad news: Bernhard Stephan, the creator of Steavens amps has retired and it's impossible to contact him.
The good news: a befriended electrical engineer told me that what I plan on doing is a "piece of cake"
Now the problematic news for which some of you might be able to help:

From what I understand, the Boss ES-5 allows for changing up to four channels AFAIU. The instructions (including a warning not to assemble your own cables lol) for how to do so are here (point 4-2): The Ultimate Guide to the BOSS ES-5 - Roland Australia (rolandcorp.com.au)

There's also another page on the Boss website where it's explained like this: ES-5: Switching Amp Channels Using CTL Output – Roland Corporation

Regarding the fact that my amp has 4 (!) channels, I am now wondering if I don't have to design the cable so that it has two jacks, like this (but not for EVH): https://btpa.com/AS-EVH10001-XX.html

Similarly, on this discussion on the Gear Page, someone confused me even more by writing this:
The instructions you quoted don't make sense to me for two channel or three channel amp's, because they say to set Ctl1 in one patch and Ctl2 in another, but for a two channel amp you'd only need one of those set on in one patch and off in the other, and for three channel you'd need to set both Ctl1 and Ctl2 on each patch, where the combination of the on/off state of Ctl1 and Ctl2 sets which amp channel is selected. (Again, depending on the amp.)

Can you confirm how the footswitch that came with your amp works? E.g., does the first switch change between channel 1 and whichever of 2 and 3 is selected by the second switch?
Others on Reddit write that it would be best do build a MIDI to 5-pole DIN cable because the MIDI output of the ES-5 is more flexible.

My problem is that I barely understand any of the underlying electrical wiring. @stratamania @mayfly could you help out by any chance?
 
Sure thing. I think your electrical engineer buddy is your best resource mind you. S/he can actually run some tests on the footswitch itself to determine what it's doing in addition to inspecting it visually. A visual inspection (something that only we could do) does not get you very far.

BTW, are those 'soft' switches on the pedalboard?
 
Regarding the comment from TGP it seems the person may be confused by the terminology.

CTL 1/2 and CTL 3/4 each have a TRS connection and need to be set for switch. If you have four presets, for example, for each channel of the amp, in each preset, one CTL 1 or 2 or 3 or 4 and only one would be active achieved by the relevant setting.

When using 1/4" TRS and CTL 1/2 JACK of a device (A = RING, B = TIP, SLEEVE = GROUND).


Regarding the fact that my amp has 4 (!) channels, I am now wondering if I don't have to design the cable so that it has two jacks, like this (but not for EVH): https://btpa.com/AS-EVH10001-XX.html

That cable has two TRS jacks, and you will need something similar with two cables terminated with TRS at one end and both connecting to the single DIN at the other. What will be ideal is if the wiring is such that CTL 1 corresponds to the cleanest channel "CLEAN" and so forth, that CTRL 4 corresponds to the dirtiest channel "HEAT".
 
Have I mentioned that I once wired a new plug on the end of an extension cord?

Ah. Was it you who did this?

56866468_1192803247536932_8156541708587237376_n.jpg
 
Regarding the comment from TGP it seems the person may be confused by the terminology.

CTL 1/2 and CTL 3/4 each have a TRS connection and need to be set for switch. If you have four presets, for example, for each channel of the amp, in each preset, one CTL 1 or 2 or 3 or 4 and only one would be active achieved by the relevant setting.

When using 1/4" TRS and CTL 1/2 JACK of a device (A = RING, B = TIP, SLEEVE = GROUND).




That cable has two TRS jacks, and you will need something similar with two cables terminated with TRS at one end and both connecting to the single DIN at the other. What will be ideal is if the wiring is such that CTL 1 corresponds to the cleanest channel "CLEAN" and so forth, that CTRL 4 corresponds to the dirtiest channel "HEAT".
Very helpful and incorporated into our planning. We have a strategy now. Will keep you guys posted.
 
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