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Trace Elliot 4001 head. Any info?

Discussion in 'Amps and Cabs [BG]' started by Groundloop, Dec 14, 2005.


  1. Groundloop

    Groundloop

    Jun 21, 2005
    Toronto
    I picked up this head used a few years ago for a song ($300 CDN.The retailer thought it was a preamp only). I don't use it anymore because I needed more power, and it sounds sort of loose and mushy to me. The DI out sounds great though, so there may be a problem with the power section. Anyway, does anyone have any info about this, such as where I could get a service manual? I ask because I would like to get it fixed and either sell it, or get a small cabinet and use it for home practice/recording.

    Spec wise the closest thing that Trace made (before they went out of business) would have been the RAH 300SMX.

    Thanks.
     
  2. Aj*

    Aj*

    Jun 14, 2005
    West Yorkshire, UK
    My guess would be at some point the front panel has had to be replaced and an SMX series pre-amp panel has been used, hence the confusion. It looks like an RAH 300SMX to be quite honest, the trafic light gain lights mark it out as an SMX or X series amp but the X series had harmonic emphasis and valve drive which this one does not. It might be a SMC series amp too, I'm not too familiar with SMC series amps, they preceeded the SMX. British audio service should have the manual you're looking for, try http://www.britishaudioservice.com/ .
     
  3. Groundloop

    Groundloop

    Jun 21, 2005
    Toronto
    Thanks for the link Aj*. I can't read a schematic to save my life, but at least I can direct the repair tech to that site when it comes to it.

    I popped the top off and the main circuit board is legended "GP12SM main" and there are a couple of stickers that state the amp was built in June of 1996. The power amp circuit board has a handwritten label that says "300w Bass".

    I'm not a Trace aficionado so I'd never even heard of the SMC series. Just another reminder of what a great resource TB is.
     
  4. Aj*

    Aj*

    Jun 14, 2005
    West Yorkshire, UK
    That's odd, the SM series didn't have the two band compressor and just had a clipping warning on the gain, not the three phase traffic light system. I'd still guess it's an SMC or an SMX based on the feature set but you'd have to wait for one of the real Trace-Heads to come along to tell you for sure, I'm not too keyed up on the years of production for Trace models.
     
  5. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    That amp is a Gibson era AH300SMX head.
     
  6. Groundloop

    Groundloop

    Jun 21, 2005
    Toronto
    Thanks Kelly.

    I just looked over the schematic for the AH300 SMX, and it certainly seems like you're correct. It looks like my head has the older Bipolar Bear power amp. In your opinion, is it worth getting this fixed? I had it serviced once before and the tech said he just re-biased the amp. It sounded good for a couple of weeks then it got loose again. British Audio Service sells replacement/upgrade power amps for $170 USD.

    Decisions, decisions.
     
  7. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    He re-biased the amp? :eyebrow: That isn't something normally associated with solidstate amps. Personally, find a new tech. Seriously.

    Given how powerful Trace amps are there is definately something wrong with the amp. My RAH350SMX is brutally loud with my 2x15 cab and your amp is only 70 watts less.

    Contact Shane at British Audio Service and see what he says about the problem. BTW, Shane is a stand up guy and won't stear you wrong. I'm sure other Trace users here will back me up on that.

    If it is just the power amp, I would definately fix it. If Shane says you need to send it in you will have to decide how much it is worth to you. What you said about "because I needed more power, and it sounds sort of loose and mushy to me" just doesn't fit the Trace sound or the typical "Trace watts" ;) That head should be able to carry you in a medium sized venue with PA support.
     
  8. Groundloop

    Groundloop

    Jun 21, 2005
    Toronto
    Yeah, I was a little leery when the tech said he re-biased the amp, because I thought that was a tube amp thing, but sure enough, there are 2 small modules on the Bipolar Bear PCB with adjustment screws, and 1 of them is labelled RV2 Bias, so there you go.

    I will get in touch with Shane at BAS and see what he has to say. Since it's so economical to replace the power amp section, I might just go that way. Combined with a Dr.Bass RX112 AirHead, I think I'd have a kick*ss little combo.

    Thanks again.
     
  9. Kelly Lee

    Kelly Lee Yeah, I'm a guy! Supporting Member

    Feb 17, 2004
    Marana, AZ, USA
    Yea, Iknow some SS heads have some sort of bias adjustment but I have never heard of any SS Trace Elliot amp ever needing to be re-biased. Oh well. :)

    Your welcome and good luck!