#110016  by TRG
 
SMS Classic - Check
Middle Super 2 coil tap - Check
UGB/OBEL - Check
JBL K120 in SSP cab - Check
MC 250 - Check...and Fail!

I've been putting my Jerry rig together for years and finally picked up an SMS in the fall and also snagged an MC250 off of ebay. When I bought the mac I did not yet have the SMS so instead of trying the mac first, I brought it straight to the amp tech for a recap/service/optimize/1/4" inputs...

The tech had it for 2 months and was extremely thorough in his work, itemizing every part and detailing every single thing that he did (with before and after pictures). Also he noted that it was testing well over 70 watts of ouput on each channel. So I finally picked it up last night swapped out the Mosvavle MV-962 for the MC250 and started playing...

Immediately I noticed that the tone was colored and not in a good way. It seemed that it was adding in a "dark color". I don't want to go as far as muddy, but almost like you had the tone knob tweaked with bass.

My problem is that I don't have anything to compare this to, as I've never played through an MC250 before, but I know this can't be right. Does anyone have the SMS> Mosvalve/MC250 combination and notice a much darker sound when swapping out the Mosvalve for the mac? When playing through the MV-962 there's no darkening/colorization of the tone. It comes out clean/clear/pronounced. The mac is thick with this darkening tonal quality to it that is swapping clarity for muddle.

So my question is, does anyone have any inkling as to what the issue could be here? I have no idea what to tell him to fix to make it "right". If I could just try one to have something to compare to I would probably be in a better situation as far as articulating the issue. :?

Any help/comments would be greately appreciated. I'm at the end of the road with this and don't know what else I can do to make this work.

Thanks!
 #110024  by mijknahs
 
What speakers are you using? Maybe the MosValve was coloring it in a brighter way and the Mac is more neutral? How about the settings of the SMS? Bass off? Treble up?
 #110025  by redeyedjim
 
Where are you? If you are in the SF Bay Area, you can compare your MC250 to my MC50.
 #110033  by TRG
 
mijknahs wrote:What speakers are you using? Maybe the MosValve was coloring it in a brighter way and the Mac is more neutral? How about the settings of the SMS? Bass off? Treble up?
I'm using JBL K120's. I also have Beyma Libertys, but have not tried those yet. I'm just not thinking that it's the speaker...so haven't tried swapping out the k120s for the Libertys.

Settings on the SMS:
Rear pad knob - Full (100%)
Bass - OFF (0%)
Treble - Full (100%)
Mid - about 1:00

Good point...maybe the MosValve was coloring it in a bright way and I've gotten used to the sound over the past couple of months, but I don't know...it just doesn't seem like the mac would be this this dark, with the SMS set the way I have it??

I keep switching back and forth between the mac and the MosValve for comparison and I can't beleive how much darker the mac seems to me?!
 #110034  by TRG
 
redeyedjim wrote:Where are you? If you are in the SF Bay Area, you can compare your MC250 to my MC50.
Thanks much for the offer redeyedjim, however I'm located in Mass :(
 #110037  by jeager
 
Sounds like something is funky to me. MC250 should sound exceptionally clear not muddy at all, even if you add some bass with the preamp...my impression was wow how very clear/clean and pleasant sounding. Nothing dark, no unpleasant qualities at all ...
 #110038  by TRG
 
jeager wrote:Sounds like something is funky to me. MC250 should sound exceptionally clear not muddy at all, even if you add some bass with the preamp...my impression was wow how very clear/clean and pleasant sounding. Nothing dark, no unpleasant qualities at all ...
Yes, that's exactly what I was expecting, so I knew immediately that something wasn't right. Now how to get "it" fixed...
 #110044  by mijknahs
 
TRG wrote: Good point...maybe the MosValve was coloring it in a bright way and I've gotten used to the sound over the past couple of months, but I don't know...it just doesn't seem like the mac would be this this dark, with the SMS set the way I have it??

I keep switching back and forth between the mac and the MosValve for comparison and I can't beleive how much darker the mac seems to me?!
I have a MosValve and it doesn't really sound drastically different from the McIntosh amps I've used (I mean my wife can't tell them apart). They both should have a similar brightness. The McIntosh should have a better "depth" to it but the brightness should be there too.
 #110045  by Pete B.
 
I have and use both of those amps.
The Mosvalve has that "Presence" knob, so if you are used to running that fully clockwise that would be as treble-ee as the Mosvalve gets. I typically run that knob around 2o'clock.
But all in all I don't notice a drastic change like you are mentioning.
The Mac is a little "Blurp-ier" in a Jerry-esque way, but I don't dectect any treble cut compared to the Moss.
I have the 962 in a rack with an Alembic F2B and Lexicon LXP-1 Reverb, as another grab and go unit.
This is all based on general use of those units, not side by side test.
I think I will be able to to do an actual side by side test today or tomorrow to simulate your issue. I will report back.
 #110046  by TRG
 
mijknahs wrote: I have a MosValve and it doesn't really sound drastically different from the McIntosh amps I've used (I mean my wife can't tell them apart). They both should have a similar brightness. The McIntosh should have a better "depth" to it but the brightness should be there too.
It's like night and day. And I was expecting exactly what your saying the mac should display and it's just not there. I can hear the magic in there and can tell it has the the sound, but it's like I'm hearing it through a thick, dark "filter".
 #110047  by TRG
 
Pete B. wrote:I have and use both of those amps.
The Mosvalve has that "Presence" knob, so if you are used to running that fully clockwise that would be as treble-ee as the Mosvalve gets. I typically run that knob around 2o'clock.
But all in all I don't notice a drastic change like you are mentioning.
The Mac is a little "Blurp-ier" in a Jerry-esque way, but I don't dectect any treble cut compared to the Moss.
I have the 962 in a rack with an Alembic F2B and Lexicon LXP-1 Reverb, as another grab and go unit.
This is all based on general use of those units, not side by side test.
I think I will be able to to do an actual side by side test today or tomorrow to simulate your issue. I will report back.
I run the presence on the MosValve around 3:00. Big time treble cut that I notice...it's like the sound frequency that I want to hear/should be hearing is muffled out or something.

Cool, thanks Pete!
 #110048  by TRG
 
Thanks for folks that have responded thus far to my issue with the mac. Much appreciated! I don't have the electrical chops to know what could be causing the issue. I know what it should not sound like though and I just don't know what component/section of the mac to tell the tech to focus on...(i.e. what could be coloring the sound like that)?

Anyone out there that has tinkered around with this and have an idea on where to tell the amp tech to focus his attention on? I mean I've read the detailed description of everything he did and what he used for parts, but it doesn't really mean anything to me. I wouldn't be able to look at it and say "ya, you don't want to use that there as it will muddy up the sound", etc... Or better yet is there anyone out there that works or has worked on a mac before and would be up for taking a look under the hood (for a fee of course)?? I'm so just afraid that if I give this back to the tech that has not used this as a Jerry guitar amp before, that I'm going to end up in an endless cycle of frustration...vs. having someone take a look that knows what needs to be in there for the purpose of a Jerryish amp.
 #110049  by Pete B.
 
Hey so the Wife and Daughter split for Target, so I just ran your test.
The Mossvalve is definately treble-ee-er.
My Dual Showman Reverb has two Pre-Amp tap outputs.
I ran one to each power amp input.
Then I switched the speaker cord (1x12" JBL-E120) back and forth several times to set levels (basement volume).
So I had the guitar on full for vol/tone knobs, and used the Standby switch during speaker cord changes, so I could go pretty quickly from amp to amp with all else being equal for the most part.
So with the left channel of the Mac at around 10 o'clock on volume, the Mossvalve Channel A was on about 9 o'clock volume.
By trial & error I found I had to set the "Presence" knob on the Mossvalve at about 10 o'clock to get the treble-ee stuff to match the MC250.
I was playing a Tiger modded Strat mainly using middle or bridge in single-coil.
I was running licks from Cumberland, West La, Slipknot, Eye's, both chords and single note runs, up and down the neck.
So I would say that if you run a test-fire with these conditions, and find it's still night and day, then maybe you could demonstrate the same test to your old (or new) Tech, for... "Furthur Diagnosis" [Oh Man, I just came up with a Furthur Tribute Band name! :drink: ].
:cool:
 #110055  by TRG
 
Pete B. wrote:Hey so the Wife and Daughter split for Target, so I just ran your test.
The Mossvalve is definately treble-ee-er.
My Dual Showman Reverb has two Pre-Amp tap outputs.
I ran one to each power amp input.
Then I switched the speaker cord (1x12" JBL-E120) back and forth several times to set levels (basement volume).
So I had the guitar on full for vol/tone knobs, and used the Standby switch during speaker cord changes, so I could go pretty quickly from amp to amp with all else being equal for the most part.
So with the left channel of the Mac at around 10 o'clock on volume, the Mossvalve Channel A was on about 9 o'clock volume.
By trial & error I found I had to set the "Presence" knob on the Mossvalve at about 10 o'clock to get the treble-ee stuff to match the MC250.
I was playing a Tiger modded Strat mainly using middle or bridge in single-coil.
I was running licks from Cumberland, West La, Slipknot, Eye's, both chords and single note runs, up and down the neck.
So I would say that if you run a test-fire with these conditions, and find it's still night and day, then maybe you could demonstrate the same test to your old (or new) Tech, for... "Furthur Diagnosis" [Oh Man, I just came up with a Furthur Tribute Band name! :drink: ].
:cool:

Very cool Pete, thanks for doing that! :cheers:

I'll give that a whirl and report back...
 #110083  by TRG
 
Reporting back on Test.

Pete, thanks for talking me off the ledge. I ran the same test and things seem much more in line (i.e.better)!

Test Conditions:
MosValve - Vol 9:00/Pres 10:00
Mac - Mono channel 10:00
JBL K120 in 1X12 SSP cab

I tried the Mosvalve first with these new settings (old settings were vol 10:00/Pres 3:00) and noticed a big difference right away...less treblee. I played for about 10 minutes with chords and single note runs.

Next I switched to the mac (at 10:00 on mono) and it sounded great and much closer in comparison to the Mosvalve with regards to tonal levels. The eagle has landed!!

Summary - A few factors came into play with my panic attack. 1.) I didn't know what the mac should sound like as I've never tried one before and didn't try it first to level set before bringing to the tech (big mistake). 2.) I was hyper-focused on treble needing to be there and any type of bass being a Jerry sound killer. The MoValve was adding more treble to my sound than I thought (especially with the presence set at 3:00) and after playing with it like that for months I got used to it.

With that said the mac is not as treblee as the MosValve, but instead has a warm character about it which is different, but GOOD! The mac also has the said "x" factor...just a culmination of certain variables that somehow all gel together and sound great flowing out of the cab. I, like other mac owners, am walking away from this test singing "I'm a believer"... :-)