I've got one for a rather cheap price for some FX addition to my board and so far quite liked it. Then after some research, I found that someone in USA (JHV3) has been making mods for this unit, which I've seen that he's retired I guess.

http://www.jhv3.com/

So, is there anyone here knows what are these improvements on the audio path that make everything more clear, more present, and such? A couple of comments around the internet say that there's a significant difference between stock and modded versions. I've opened up the unit to change one of the buttons that works bad, and saw that it mostly consists of SMT parts, apart from polarized caps which mostly are thru-hole type.

Any feedback is appreciated.

Hmm I read this in the description of the mod:

QuoteThe Short of it:
The signal path between the input and output is upgraded and altered with audiophile grade passive and active components to maximize the efficiency of the stock CODEC. The analog to digital conversion process is fed a more pristine signal with extended headroom and added muscle from the power "rails". Between the balanced CODEC output to the line level outputs, the signal path is streamlined to invigorate and protect the integrity of both affected and clean tones. Leaving the pedal in DSP bypass or "spillover" mode is no longer at the expense of your tone.

There is a lot of marketing nonsense so I'm a bit sus. What I suspect the upgrade to be is that the opamps (M5 uses a TL07x so these are in fact quite decent) are swapped out for rail-to-rail types. And probably the elco's swapped for audio grade? That would be my guess at least.

Quote from: niektb on May 13, 2024, 01:59:52 PMThere is a lot of marketing nonsense so I'm a bit sus. What I suspect the upgrade to be is that the opamps (M5 uses a TL07x so these are in fact quite decent) are swapped out for rail-to-rail types. And probably the elco's swapped for audio grade? That would be my guess at least.

+1 agree. I would also suspect that a couple of values get tweaked to raise LP cutoffs a bit. Perhaps they were fairly dark originally? Dunno. Tastes vary, and fashions change too.

There's a schematic here, maybe it'd make some sense. Way too hard for me, though.

https://www.freestompboxes.org/viewtopic.php?t=16728

I was actually just playing with my M5 an hour ago.  One of the interesting things about the M series, and many other pedals with stereo ins and outs is that they can be used for "reprocessing".  That is, you plug into the "mono" input, take its output and feed that to the other input, and use that second output as your mono output to the amp. It's not true of ALL 120+ effects, but many of them can produce some very interesting and unique sounds when the signal is processed a second time.  My favourite is reprocessing the reverse delay, but many others will work too.

One of the things that the M9 provides, which my M5 doesn't, is the ability to have more than one effect in series.  I have used my Line 6 Echo Park and Liqui-Flange in reprocessing mode (with stereo docks, of course), such that the signal goes through one channel of each, in series, then gets fed back to the other input of the first pedal, and the final result is wonderful.  You may be able to do that without patch cables on the M9.

It's one of those things that I wish was demonstrated more often.  I should probably make a Youtube.  Tomorrow.

Quote from: Mark Hammer on May 13, 2024, 04:29:03 PMI was actually just playing with my M5 an hour ago.  One of the interesting things about the M series, and many other pedals with stereo ins and outs is that they can be used for "reprocessing".  That is, you plug into the "mono" input, take its output and feed that to the other input, and use that second output as your mono output to the amp. It's not true of ALL 120+ effects, but many of them can produce some very interesting and unique sounds when the signal is processed a second time.  My favourite is reprocessing the reverse delay, but many others will work too.

One of the things that the M9 provides, which my M5 doesn't, is the ability to have more than one effect in series.  I have used my Line 6 Echo Park and Liqui-Flange in reprocessing mode (with stereo docks, of course), such that the signal goes through one channel of each, in series, then gets fed back to the other input of the first pedal, and the final result is wonderful.  You may be able to do that without patch cables on the M9.

It's one of those things that I wish was demonstrated more often.  I should probably make a Youtube.  Tomorrow.

Well, i would never think about it for a lifetime if you would not mention about it. Its so basic, yet effective approach!

Quote from: ElectricDruid on May 13, 2024, 02:55:11 PM

Quote from: niektb on May 13, 2024, 01:59:52 PMThere is a lot of marketing nonsense so I'm a bit sus. What I suspect the upgrade to be is that the opamps (M5 uses a TL07x so these are in fact quite decent) are swapped out for rail-to-rail types. And probably the elco's swapped for audio grade? That would be my guess at least.

+1 agree. I would also suspect that a couple of values get tweaked to raise LP cutoffs a bit. Perhaps they were fairly dark originally? Dunno. Tastes vary, and fashions change too.

Aaah yes, that makes sense as well.

Quote from: Baran Ismen on May 13, 2024, 04:12:15 PMThere's a schematic here, maybe it'd make some sense. Way too hard for me, though.

https://www.freestompboxes.org/viewtopic.php?t=16728

Oooh nice, I was looking for that as well but couldn't find it! Interesting schematic! There is 2 things I don't understand though. On the input they split it up and apply a bunch on gain to one copy? But everything goes to the same codec.



For the output as well, they have gain in the output filter but immediately divide it down. Are they afraid of opamp instability with unity gain? it explains why they use -12V and +12V but I'm not sure why one would do this

Quote from: niektb on May 14, 2024, 05:11:28 AMOooh nice, I was looking for that as well but couldn't find it! Interesting schematic! There is 2 things I don't understand though. On the input they split it up and apply a bunch on gain to one copy? But everything goes to the same codec.

They've got a "low gain" and a "high gain" version of the signal going to the codec. The DSP chip can then choose to use whichever it thinks is most appropriate based on the incoming signal level. That makes best use of the available ADC resolution.
They also use a simple inverting op-amp to flip the signal so they can provide the input as a differential signal to the codec. This probably gets a slightly better SNR out of the codec than using it single-ended.

QuoteFor the output as well, they have gain in the output filter but immediately divide it down. Are they afraid of opamp instability with unity gain? it explains why they use -12V and +12V but I'm not sure why one would do this

Yeah, I agree that the x3 gain in that filter seems a bit odd.

I was looking at that Page 8 "analog output" schematic, trying to see what someone might have altered to claim that they'd upgraded the audio output. The things that I would look at are:

1) Those 10uF electrolytics (C167/C161)
It's going to spend half its life reverse-biased, isn't it? Put in a bipolar audio-quality cap instead, maybe?
2) The 10nF caps (C30/C25)
The cutoff for these seems to be around 20KHz when combined with the 2.74K/953R combination. So although this looks like a lowpass on the output, it doesn't look like it's significant.

Beyond that though, I can't really see *anything* much that would even make me think "Oh, I bet they changed that!".

Quote from: ElectricDruid on May 14, 2024, 07:11:41 AMIt's going to spend half its life reverse-biased, isn't it?

No. The voltage across a coupling cap "does not change" over an audio cycle. If it did it would be Bass Loss.

Quote from: PRR on May 14, 2024, 07:08:25 PM

Quote from: ElectricDruid on May 14, 2024, 07:11:41 AMIt's going to spend half its life reverse-biased, isn't it?

No. The voltage across a coupling cap "does not change" over an audio cycle. If it did it would be Bass Loss.

Yeah, true. I wasn't thinking straight. Thanks for clearing that up, Paul.

So there's nothing much to "fix" in that output schematic at all, in truth. I wonder what they were doing?

The gain is (I assume; too lazy to figure) "needed" to put a nice sharp corner on the high-cut, to knock-down the supersonic digital garbage with little effect on audible audio. I'm more a Sallen-Key guy where 1.6X is nominal and over 2X oscillates, so I agree this one looks extreme, but they knew their stuff.

However, using blue capacitors always sounds better.

Ya know, this filter might be a hundredths-% cleaner with a '5532 bipolar than a TL0xx bifet, only because the popular-price bifets are known for common-mode distortion. On a "modeler" which models distortions, this may be a pig on lipstick, but some folks get into that.

Quote from: Baran Ismen on May 14, 2024, 12:48:36 AM

Quote from: Mark Hammer on May 13, 2024, 04:29:03 PMI was actually just playing with my M5 an hour ago.  One of the interesting things about the M series, and many other pedals with stereo ins and outs is that they can be used for "reprocessing".  That is, you plug into the "mono" input, take its output and feed that to the other input, and use that second output as your mono output to the amp. It's not true of ALL 120+ effects, but many of them can produce some very interesting and unique sounds when the signal is processed a second time.  My favourite is reprocessing the reverse delay, but many others will work too.

One of the things that the M9 provides, which my M5 doesn't, is the ability to have more than one effect in series.  I have used my Line 6 Echo Park and Liqui-Flange in reprocessing mode (with stereo docks, of course), such that the signal goes through one channel of each, in series, then gets fed back to the other input of the first pedal, and the final result is wonderful.  You may be able to do that without patch cables on the M9.

It's one of those things that I wish was demonstrated more often.  I should probably make a Youtube.  Tomorrow.

Well, i would never think about it for a lifetime if you would not mention about it. Its so basic, yet effective approach!

I mistakenly posted this in another thread, and meant to post it here.

I've had 2.  The first one had some sketchy buttons so I replaced them with regular stompbox momentaries.  That is something that in retrospect I would have been glad to pay someone $75 to do.  I didn't bother with the signal path mods.  Sold that one, for some reason got another and gave it to a friend.  I had an HX Effects for awhile too, sold that as well.  You'd think I don't like effects!!!!      

Quote from: Digital Larry on May 15, 2024, 11:21:11 AMI've had 2.  The first one had some sketchy buttons so I replaced them with regular stompbox momentaries.  That is something that in retrospect I would have been glad to pay someone $75 to do.  I didn't bother with the signal path mods.  Sold that one, for some reason got another and gave it to a friend.  I had an HX Effects for awhile too, sold that as well.  You'd think I don't like effects!!!!      

Did you use these? Would they fit into there? Any further tinkering was needed?

https://www.thomann.de/gb/tad_footswitch_momentary_spst.htm

Yes,something very much like that.

Quote from: Mark Hammer on May 15, 2024, 08:12:06 AM

Quote from: Baran Ismen on May 14, 2024, 12:48:36 AM

Quote from: Mark Hammer on May 13, 2024, 04:29:03 PMI was actually just playing with my M5 an hour ago.  One of the interesting things about the M series, and many other pedals with stereo ins and outs is that they can be used for "reprocessing".  That is, you plug into the "mono" input, take its output and feed that to the other input, and use that second output as your mono output to the amp. It's not true of ALL 120+ effects, but many of them can produce some very interesting and unique sounds when the signal is processed a second time.  My favourite is reprocessing the reverse delay, but many others will work too.

One of the things that the M9 provides, which my M5 doesn't, is the ability to have more than one effect in series.  I have used my Line 6 Echo Park and Liqui-Flange in reprocessing mode (with stereo docks, of course), such that the signal goes through one channel of each, in series, then gets fed back to the other input of the first pedal, and the final result is wonderful.  You may be able to do that without patch cables on the M9.

It's one of those things that I wish was demonstrated more often.  I should probably make a Youtube.  Tomorrow.

Well, i would never think about it for a lifetime if you would not mention about it. Its so basic, yet effective approach!

I mistakenly posted this in another thread, and meant to post it here.

Gave this a try, it really produces pure insanity, I'd say!

Another thing came up to my mind is that; in my pedalboard, some effects I use pre and most of them as postamp, and my preamp unit is a Mooer X2, which I like it. Say; i'd make a connection like this, would it work like a pseudo-order switch, else I'll have to make a small stomp with a 4DPT switch with 6 ts sockets to make the whole unit to work as pre or post-amp.

input -> preeffects -> left input of M9 -> left output of MP -> input of X2 -> 10 Band EQ -> right input of M9 -> right output of MP -> post effects -> output