I have an odd SM-400 that hopefully someone may be able to help me figure it out. From all the specs I have read and the fact thats all its marked as it is a standard SM-400 but it has th extra knob the SM-400S has on the front panel. Has anyone heard of this or is able to shed any light on this matter? Ill post pics asap.
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SWR SM-400 question
- Thread starter JonYouth
- Start date
The effects blend knob is labeled "Transparency" on my 400S. I keep it all the way up for the most part since my Sansamps run through the effects loops.
Back in the day when Steve Rabe owned SWR, they were very consumer friendly
I had bought a very early SM400, which did not have the transparency control
A year or so later, they added this feature although the amp name did not change
I called the factory to explain that I would like to pay to have this feature added if possible; ended up talking to Steve who charged me $35 and paid the return shipping
He added the circuit, pot, checked the amp for proper performance (it actually put out something like 450 watts bridged at the rated distortion level) and paid the shipping back
Needless to say, they were not able to gut the amp for this price to put on a new silk screened front panel. Great customer service and pro level support for just regular guys.
And now you know!
I had bought a very early SM400, which did not have the transparency control
A year or so later, they added this feature although the amp name did not change
I called the factory to explain that I would like to pay to have this feature added if possible; ended up talking to Steve who charged me $35 and paid the return shipping
He added the circuit, pot, checked the amp for proper performance (it actually put out something like 450 watts bridged at the rated distortion level) and paid the shipping back
Needless to say, they were not able to gut the amp for this price to put on a new silk screened front panel. Great customer service and pro level support for just regular guys.
And now you know!
There were also factory mods for a headphone jack, moving the effects loop to pre-master volume and adding a variable pad and ground lift to the DI. Basically you could add all the features of an S model (and then some) to a 400.
If you look at the schematics, you will see that you can even raise the output of a 400 to 500 levels by swapping out a bunch of passive components. Heat dissipation becomes much more of an issue which is why, I imagine, they had to add the fan to the S and subsequent 500 models.
If you look at the schematics, you will see that you can even raise the output of a 400 to 500 levels by swapping out a bunch of passive components. Heat dissipation becomes much more of an issue which is why, I imagine, they had to add the fan to the S and subsequent 500 models.
The front looks exactly like my 400S to a T....well almost. The knob underneath the treble knob on yours looks like it's not labeled. On mine that's a "transparency" knob, basically a high treble knob, higher than the one labeled treble. I don't know what effects blend knob they're talking about. Plug straight into the amp, hook it up to something with a tweeter in it and turn that knob all the way left to right and see if it changes highend content or not. If it does, it's an unlabeled transparency knob, if it doesn't, it may be an effects blend so then try it with some effect and see if it affects that.
Mine has a cooling fan mounted in the middle of the amp (not visible from the outside) that blows down the heatsinks and out the side. If I remember right (have to look up the manual again) my XLR DI out is pre-eq and the 1/4" jack label "line out" is post eq.
If anybody has any mod links, I'd like to fix my DI and put a pre/post switch and a level control on it. Search "aural enhancer mod" on here to see how to re-voice the amp, actually level it to a more even output instead of being pre-voiced.
Mine has a cooling fan mounted in the middle of the amp (not visible from the outside) that blows down the heatsinks and out the side. If I remember right (have to look up the manual again) my XLR DI out is pre-eq and the 1/4" jack label "line out" is post eq.
If anybody has any mod links, I'd like to fix my DI and put a pre/post switch and a level control on it. Search "aural enhancer mod" on here to see how to re-voice the amp, actually level it to a more even output instead of being pre-voiced.
Yes
It actualy started on the 220 watt model head as I understand it
In regards to the headphone mod, I was directed to an SWR guru through this board and asked about the headphone mod; he said that it was done at the factory to Randy Jackson's amp but didn't think that the factory did any others
I'm looking at my Guitar Center invoice. As not an expert on SWR gear, I bought a used amp labeled in the description as a SM400s. However, on the front panel it just says SM400. Apparently they labeled it as a 400s but the actual amp they sent me is just a regular 400. Too bad I didn't ask for clarification before I bought it. I didn't know there were different incarnations of the SM400.
Looks like the Transparency control mod. I had that done on my SM400 and it was in that spot on the control panel. You can use your ears to determine if it is - just turn it up and see if you hear an increase in the extreme treble region.
