SUNN Sceptre - Question about usage with bass.

[slavestate]

Hello there,

I might be picking up a Sceptre head that I would be using for bass. I have a 4x12 Acoustic Control cabinet that I would be playing it through which is 4 Ohms. The band that I play in uses two 50 watt guitar amps into 4x12's and we play almost at full volume on the guitar amps.

My question is, with this amp being around 60 watts RMS (?) would it be able to be heard through the mix?

I would be purchasing it as an investment regardless if it didn't work for bass, however I would like to use it in this application.

Any comments would be greatly appreciated.

Thank you.

[loudthud]

It depends on what kind of music you play, but offhand I would say you need at least 120W and more speaker cabinets.

[slavestate]

We play heavy blues rock stuff. We're looking for a bass amp with a bit of a overdrive bite, yet still retaining some clarity.

I jumped on the purchase of the Sceptre, and I'll know by late next week if it will do the trick. If not, we'll have a great back up head.

Thanks!

[EdBass]

The band that I play in uses two 50 watt guitar amps into 4x12's and we play almost at full volume on the guitar amps.

Two 50 watt tube guitar amps into 412 cabs at almost full volume can make quite a racket. I'm afraid trying to keep up on bass using a single Sceptre into a 412 would be difficult at best.
Maybe with a couple of efficient 215 cabs...

[Soundmasterg]

If you like flat out distorted bass, then maybe, but probably will not keep up with those guitar amps. Where do you play that loud anyway these days! You could keep up if you miked the amp or installed a line out in the amp and ran it into a PA, and if you had multiple speaker cabinets that were very efficient....but otherwise it will be a distorted beast that won't be loud enough.

Greg

[slavestate]

I could always run a power amp with the Sceptre as well right?

[EdBass]

I could always run a power amp with the Sceptre as well right?

Theoretically, but you would need to modify the Sceptre by adding a line out. You should make sure the drivers in that Acoustic cab are up to the task of handling the extra power also.
You would probably by better off just getting a bigger integrated bass amp; mass produced Asian transistor bass amps are dirt cheap on the used market. You could probably get a multiple 500+ watt 5-10 year old transistor bass amps for what you could sell the Sceptre for.

[slavestate]

With the power amp I wouldn't be able to run from an input out into the power amp? I would have both the Sceptre and power amp hooked to a speaker cabinet.

[Isaac]

With the power amp I wouldn't be able to run from an input out into the power amp? I would have both the Sceptre and power amp hooked to a speaker cabinet.

Nope. No more than you can plug your bass straight into the power amp. However, it's not hard to make a line out box. I made one in a plastic deli container. Input jack (from the speaker out on the head), output jack (to the speaker), line out jack (to the external power amp), and two resistors to drop the voltage. 10K in series with the line out jack and 1K in parallel yields 2 volts at 60 watts from the 8 ohm jack. That should be plenty to drive most any amp.

[BassHog]

Now Correct me if I'm wrong, but isn't the Sceptre the same exact amp as a 200s but with Reverb and Tremolo?
Same Power section and output right?
Why wouldn't it be just as loud and sound just a good as a 200s for bass? The circuit doesn't look much different other than the effects.
People gig regularly with their 200s rigs right?

You can also convert it to a solid state rectifier and run KT88's in it for some extra power. Mine came tube rectified with 6550's. You will want to upgrade the filter caps before you do this though, but this should be done anyway as the voltages in the amp are too high for the caps in it's stock form these days due to higher wall voltage.

[EdBass]

It's pretty much the same amp as a 200S with reverb and trem and some tone stack differences.
I don't think the issue is the ability of the amp, I think it's the fact that it's going into a 412 guitar cab, competing with a pair of 50 watt half stacks and they "play almost at full volume on the guitar amps".

[slavestate]

The Sceptre arrived to me today. I must say that it is pretty damn loud. I played both guitar and bass through it in all of the inputs to get a feel, but this Sunday we will give the head a try in a rehearsal setting and see if it's something of use.

I noticed that some modifications have been done in the past, so I don't know if it's 100% or what. I did notice some feedback squeals at high volume as well as some high frequency bits that were cutting through when I used it with bass. I am going to anticipate a re-cap as well as new tubes all around. The tremolo seems to be working okay, but may need to be looked at. Same for the Reverb. I've got some time to think about if it's worth keeping or send back, knowing I'll have to sink a couple more hundred into this I might just opt out of making lemonade out of a lemon.

It also seems like there might have been a master volume potentiometer installed at one point.

Besides what I mentioned above when playing it with my Gibson SG standard and it sounded wonderful with that, and with my pedal board running various delays and phasers it handled them nicely. There is a ton of low end that comes out of this amp and it's such a relief.

It has 6550's in it now, and the chassis is dated October of '68. I'm not too sure all of the tubes are good, so I'll have to have an EE buddy of mine take a look at this guy.

I'm going to start looking for schematics.


In regards to that line out box, I might just put one together. I just picked up an Alpha Slave, which would be cool to push this guy with.

More to come.

[Isaac]

For what it's worth, I rehearsed today with my Sentura II (same amp as the Sceptre) running into my 200S cabinet. Sounded really sweet.

[buzzsunn]

If your amp needs a service, consider changing to KT88s. You can also try to replace the tube rectifier to a solid state one (a simple change that is reversible). Lots of bassists seem to do these!

And congrats for your purchase! It's a great amp.