NBAD Trace Elliot 712 SMC

[SkyMonkey]

Almost on a whim, I decided to trade in some unused pedals and my Fender Rumble 25W bass practice amp, and bag a fairly tidy Trace Elliot 712 SMC combo for £149 (£60 after the trade).
It's 130W (well, maybe 75W without another 8 ohm cab plugged in) and has a 7 band EQ and compressor onboard, D.I. out and an FX Loop.
12" 8 ohm speaker that I've not had a look at yet (bit dusty).
Whacked up the volume in the shop and no rattles!
I'm really liking it (with my scant expertise on bass amps).
I am having a bit of trouble actually dating the combo, but maybe sometime in the late 90's or early 00's?
If anyone knows anything about the 712 SMC please post here, coz there's not much available online.

Gotta resign from the Rumble Club now!

 

[abarson]

That’s a very clean looking combo. Enjoy!

 

[Hawk256]

Very clean. Nice score. From my understanding the SMC is mid 90's before Gibson. Someone can correct me if I am wrong. If you pull the head part out of the combo there should be date on the QC sticker. I am looking at a 7210 SMC right now. You may have given me some bargaining power.

 

[SkyMonkey]

I am looking at a 7210 SMC right now. You may have given me some bargaining power.

Cheers @Hawk256.

But now that I have this one home, I am noticing a hum (60Hz?) that may become intolerable unless there is a solution.
I think the shop was too noisy for me to have heard it (and I did try to listen).
It is a high pitched hum that is definitely from the power section, as it it goes up in volume with the Master, but not Gain.
A cable in the Return isolates the preamp from the power amp (i.e. series loop), and the hum persists.
This is either with an input cable or without, and none of the other controls effect it.
I suspect the fan is to blame, so a new one could help if the old one is original.
BTW, I run another SS guitar amp and a tube one too. Neither has the same hum (not the power supply?).

So, are there any general suggestions as to how 'amp hum' may be remedied?
I am looking into how to pull the chassis today.

 

[Hawk256]

Cheers @Hawk256.

But now that I have this one home, I am noticing a hum (60Hz?) that may become intolerable unless there is a solution.
I think the shop was too noisy for me to have heard it (and I did try to listen).
It is a high pitched hum that is definitely from the power section, as it it goes up in volume with the Master, but not Gain.
A cable in the Return isolates the preamp from the power amp (i.e. series loop), and the hum persists.
This is either with an input cable or without, and none of the other controls effect it.
I suspect the fan is to blame, so a new one could help if the old one is original.
BTW, I run another SS guitar amp and a tube one too. Neither has the same hum (not the power supply?).

So, are there any general suggestions as to how 'amp hum' may be remedied?
I am looking into how to pull the chassis today.

Does changing the ground lift switch in the back make a difference in the hum?

 

[SkyMonkey]

If you pull the head part out of the combo there should be date on the QC sticker.

8/95 on the transformer coil, so August 1995. But 24/3/96 on the PCB.

Does changing the ground lift switch in the back make a difference in the hum?

No ground lift on the back. Back Panel Facilities - TRACE ELLIOT SMC RANGE Operating Instructions Manual [Page 8] | ManualsLib

I have now had a poke around inside and found nothing untoward, except maybe the fan is what I can hear mostly at bedroom levels.
The hum is mainly noticeable when directly in front of the cone, and I have perched the amp on a small table type thing to access all the sockets for the three amps and pedal power warts underneath.
I am new to this 'proper bass amp' business, having only had small wattage practice amps before now.
Maybe it's operator error.
I think I'll look into getting a better 80mm fan.
All the dust is now gone too and it looks pretty tidy!

Anyhow, for future seekers, here are all the pics that I couldn't find online:

 

[SkyMonkey]

 

[SkyMonkey]

Dimensions: H 23" (560mm) / W 18 3/4" (475mm) / D 13 1/2" (343mm).

If I take the front panel PCB off in the future I'll post pics.

 

[Hawk256]

Thanks for the pics. There are many reasons that you can hear a hum so it's sometimes not easy to track down without a lot of trial and error. I have a Laney RB2 practice amp that hums if there is no ground on the outlet. Sounds fine on a grounded outlet. It's possible that what you are hearing in a quiet bedroom may not be noticeable in a band environment. It's also possible that you are getting the hum from the pickups of the bass if you are standing directly in from of the amp. Step back a couple of meters and see if you still hear it.

 

[SkyMonkey]

I don't really have a couple of meters to spare in the room! LOL

It's fine. The hum almost disappears when I stand a bit off-axis, and the amp is setup about a foot and a half away from a plastered wall and sloping ceiling under the roof in a converted loft (see the pic).
That's why I can hear the fan noise reflected back at me (never had a fan cooled amp before either).
BTW I did use a pencil to stop the fan momentarily but the hum was still there, so the actual fan isn't being picked up.
And the pickup on the bass is a Bartolini humbucker, so it shouldn't be the problem.
I'll look into how I might clean up the power (it is grounded) and get a quieter PC fan.

Cheers @Hawk256 and post if you do go for the 712 you've seen.

 

[PeaveyPlayer]

How do you like the 7 bands of Eq?

 

[SkyMonkey]

How do you like the 7 bands of Eq?

It's the first physical graphic EQ I've had, and the compressor too (only multi-effects ones so far).
So the whole amp is a step up in power and features from anything I've had before.

I need to set up a looper to dial it in soon, when I can make some noise (work at home partner!).

And a speaker change may be on the cards if I bond with the amp.
The stock BG12S-100 is pretty near the max output of the amp without a cab attached (I've seen estimates of 95W?).
I can't find any specs on it, but I suspect it's pretty low efficiency.
So, at least a Pulse 12 (94dB), but maybe a BN12-300S (99dB).

 

[Sparky Mark]

Beware of changing the cooling and/or speaker without making really sure that they are both designed to do the same job as the originals. The wrong fan may work adequately at bedroom levels but the amp could overheat quickly on a gig if it can't achieve the same airflow through the system. Likewise, the replacement speaker might not give you additional output if it isn't designed to work in the combo's internal volume or port tuning and might sound uneven through the frequency range.

 

[mingustoo]

I love these amps. I have the GP12SMX- 12 band eq and two band compressor and an eq balance. Brilliant!

 

[SkyMonkey]

Beware of changing the cooling and/or speaker without making really sure that they are both designed to do the same job as the originals. The wrong fan may work adequately at bedroom levels but the amp could overheat quickly on a gig if it can't achieve the same airflow through the system. Likewise, the replacement speaker might not give you additional output if it isn't designed to work in the combo's internal volume or port tuning and might sound uneven through the frequency range.

OK, point(s) taken. Cheers @Sparky Mark. The original fan is still for sale new so that may be a better buy.
And the speaker seems to be in good condition, so maybe I'll keep with it until it isn't!