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Laurie
Double Platinum Member
Canada
4854 Posts |
 Posted - 08/09/2008 : 02:56:48
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OK... I just did an A-B between the MT-2 and XT-2 and they aren't really that similar (my memry was deceiving me).
MT-2 sounds good cranked. Not sure what it sounds like, but it isn't like a stock MT-2 anymore.. AT ALL.
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/11/2008 : 03:52:12
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Yeah... it's good.
MOSFETs plus a bunch of other tweaks and it is "done". Soemthing I can definitely live with.
My thanks particularly to MoonWatcher for the great info on MOSFETS in this and other threads. |
Edited by - Laurie on 08/11/2008 05:30:08 |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 08/11/2008 : 18:30:22
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Glad to be of help!
When you get a chance, try dropping a pair into the FB loop of an OD pedal... |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 08/12/2008 : 04:16:36
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I think that I'm finally content with this ped as well...
I got my 2N700's in, and bumped up all 10pF & 47pF with 100's, and the pair of 100pF's with 220's.
This thing finally sounds sweet. The mos's really allow the headroom to pump up, but sound much rounder and thicker than other higher threshold diode combinations. Those combined with the bigger brights, the stock Mitsubishi chips are now properly compensated for.
A very unorthodox method for souping up the MT-2 compared to what most modders are doing, but it seems to work... |
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Dingus
Silver Member
USA
472 Posts |
Posted - 08/12/2008 : 14:33:04
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| This thread had me revisiting my MT-2, and my recent ML-2 that I just got from a pawn shop. I was listening to Keeley's clips on his website, and I must say that the ML-2 sounds a lot like the keeley-modded MT-2 clips to me... any one else hear that? |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/12/2008 : 15:06:46
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quote:
Originally posted by MoonWatcher
I think that I'm finally content with this ped as well...
I got my 2N700's in, and bumped up all 10pF & 47pF with 100's, and the pair of 100pF's with 220's.
This thing finally sounds sweet. The mos's really allow the headroom to pump up, but sound much rounder and thicker than other higher threshold diode combinations. Those combined with the bigger brights, the stock Mitsubishi chips are now properly compensated for.
A very unorthodox method for souping up the MT-2 compared to what most modders are doing, but it seems to work...
Hi MoonWatcher
I know I always ask the hard questions.
But is there any way that you can post a link to some sound files of your Modded MOSFET MT-2?
I know there are a lot of other members here, that would be keen to hear your work as well.
Regards Dr. Bob
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 08/12/2008 : 22:39:29
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Hey Good Doc -
I'll try to record and upload some files before week's end (I have a bunch of "obligations" to attend to first).
I'm actually anxious to get all of my stuff uploaded, but I guess we'll start w/the MT-2. |
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Von
Copper Member
Australia
26 Posts |
Posted - 08/14/2008 : 00:56:42
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| A photo or 2 of the PCB would also be nice. |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 08/14/2008 : 05:30:45
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I'd love to oblige with some pics, but there's enough residual Allums Sustainia parts that it might just be a no-no.
Also - not too much to look at! The 2N700 pair look like just another pair of NPN's, most of the add'l film caps that I tweaked were also AVX's. The brights are just cheap ceramics like the originals.
I really want to pull the tantalums. Not so much a tone issue as the fact that they hate inverted current. Nonpolar e's are perfectly sufficient, IMO. |
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mojah63
Copper Member
USA
10 Posts |
Posted - 08/26/2008 : 17:05:32
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Hey Moonwatcher,
I did the MA Sustainia too and was not impressed.
Did you leave monte's changes in place then add your own? I gave up
after a while with mine but now I'm intrigued with some of your
changes esp the mosfets.. My OCD has them in it... |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 08/30/2008 : 15:06:51
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Hi Mojah -
I did leave most of the Allums stuff in mine.
But I swapped out some things that the Sustania mod never addressed:
- C36 should be increased, IMO. I like .068 uF, but that may be too high or low for you.
- The bright caps in the feedback loops must be increased to reduce the harshness. Most modders neglect these little ceramic caps. The ones you need to change are C10, C18, C22, C26, C28, and C32. They are as small as 10 pF, and as big as 100 pF. If you like the OCD, you may want to try what it uses - 220 pF. Depending on how much you want to "round off" the top end, you can jump to 470 pF, or even .001 uF or .0047 uF. All of these cheap ceramics are available at Rat Shack for like $1.50 for two, so it's a cheap experiment. I suggest you start with 220's, since you like the OCD. Change all 6 to the same, IMO.
- The other thing I have yet to do is replace the Allums Tantalums - I think there are two in the Sustania? Tantalums sound kinda brittle to my ears - not sure why. I know that they can't stand inverted DC current, and when the chips swing hard to the rails, you can sometimes get an inverted DC dump that almost makes the pedal sound like it's cutting out. I'm currently having a love affair with nonpolarized electrolytics. Great sounding caps.
The mosfets go in where the diodes were. They have THREE leads - G, D, and S. The G and D get soldered together (I bend the D to a right angle and solder it to the G up near the case, and clip off the excess). When you install them, make sure that they are oriented like diodes - have G&D end pointing "North" on one, and "South" on the other (like the stripes in a diode).
The above sounds like a lot, but is really pretty minimal. If you simply replace the diodes and 6 bright caps, you'll probably be happy, and can forget about C36 and the tantalums. |
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mojah63
Copper Member
USA
10 Posts |
Posted - 09/03/2008 : 12:31:16
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Thanks MoonWatcher... I had changed c36 already to .1uf. That did
make the mid control better. I socketed most of the cap mods so I
should just be able to plug and play. Tants are a weired beast...
The only one in an OCD is critical for it's "sound" but I can take
or leave them. Personally I like the yellow box AVX caps for some
applications never tried np electrolytics hmmm ... I think you may
be right about the treble bleeds. Stock it's a high mid mush machine
with little note articulation. My Fab Tone is better..
Now, I'll have to make some time to get back to my mt-2 now ;)
Thanks Again,
P |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 09/03/2008 : 18:37:50
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I've finessed the 6 brights a little more, to kill some more fizz...
I forget which is which, but here's my breakdown for how I bumped them up:
Stock value of 100 pF - bump up to 390 pF (first and last in the circuit?)
Stock value of 47 pF - bump up to 220 pF
Smallest stock caps (~10 pF?) - bump up to 100 pF
This allows you to really crank the drive without any splat. If you run the distortion lighter, drop one or both of the (new value) 220 pF caps back down to 100 pF, if you find that it get's a little too dark.
I also cut the value of C44 (treble cap) down from .01 uF to .0047 uF, with negligible results. I suggest that this cap be left alone, since it's a bear to get to. |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 09/05/2008 : 00:00:33
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I don't have the MT2 but If I had one I would try changing R34 to something like 6.8k or even 10k. This is an RLC simulating gyrator but the center frequency is set to 4894 Hz. This is way to high.
A value of 10k will set it to 1547 Hz which is more HM2 territory.
Just my 2 cents. |
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MoonWatcher
Bronze Member
USA
98 Posts |
Posted - 09/05/2008 : 15:52:41
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I would diddle with R34, but I've pulled C24, completely disabling that gyrator.
Plus, most folks pull C25 anyway. That's usually sufficient to nuke the "trumpet blast" upper mid boost. |
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Topic |
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Keeley mod for MT-2
