Promethean

[gafbass02]

Just wondered, promethean owners, how many of you have the promethean as your main/only amp?

[wateroftyne]

Here's a bit of info which might be useful to anyone who has had an experience with a noisy / underperforming Promethean.

I've done a lot of gigs with mine over the best part of a year, and noise-wise it's been - as near as damn it - dead silent. I love it.

However... as I was plugging in to the amp at a gig a couple of days ago, I noticed the nut around the input jack had worked a little loose. As a result the socket had a bit of a wobble so I instinctively hand-tightened the nut. Presumably, as I did this, the assembly behind the face plate rotated a little too.

Anyway, since then I noticed two things... at the gig, I had to drive the amp a lot harder than I normally did. Secondly, when I used the amp at home afterwards, I noticed it had begun to hiss. Badly.

I've just spent some time trying to work out what the problem is, and as part of the troubleshooting I thought I'd hand-turn the nut around the jack anti-clockwise back to where it was.

Bingo! The power & punch is back, and the hiss is gone - night-and-day in a quarter-turn.

So... all I need to do is pop the top off the amp and tighten the nut properly, keeping the assembly stationary.

Could explain the hiss / noise issue a few people have had...? Until I get into the amp, I couldn't begin to explain what's going on behind the scenes, but if I work it out I'll post it here.

Hope this helps!

[gafbass02]

Wow eagerly awaiting more on that! Weird! I still fancy one loads

[krazy_olie]

draggin up an old thread here... but my new Promethean is hissing...
There are two sources, one is the pre-amp which is normal, increases with gain treble etc, that's not the issue though..
There is a constant hiss even when muted with nothing plugged in and it is independent of the gain and master and tone controls. It does seem to slightly change when I hit the EQ on and off (this is still muted). I don't think this hiss propagates to the headphone socket but I need to investigate that further, but the speaker does still hiss when headphones are plugged it.
It seems to get a little bit louder/changes frequency after the amp being on a few seconds, then stays constant.
It's not very loud, probably without the tweeter it would be fairly quiet but it is certainly noticeable.
Don't know if I should take it back or not, it can't be replaced as there aren't any more units left!

I took the top off to look at the jack input as mentioned above and I couldn't see anything obviously wrong with it, although I do feel it might not be quite right at lower volume so could well be the same issue.

Any thoughts/suggestions?

[gafbass02]

I had the same problem mate. It had to go back

[deanovw]

I would be interested in any comments on this as mine is developing a hiss too. I cant take it back as I got it second hand.

[wateroftyne]

It's a shame hearing about all these hissy ones... At this moment I'm in the a conservatory having an acoustic rehearsal and, although there is a hiss, it's barely noticeable.

If I turn the output up to a level where hiss is audible, the actual output of the amp at that level is deafening. You would expect hiss at that volume.

[krazy_olie]

so i opened it up and now I'm 90% sure it has a dodgy capacitor, i can hear it hiss inside the amp itself. I can't pin down the exact component but it's likely.
They are probably el cheapo chinese caps which would explain why this problem crops up. Will speak to the shop and see what they say but I think this is quite fixable.
Apart from that it sounds awesome.
Deanow i would suspect yours has developed a similar issue, I.ll let you know if my suspicions are right, if they are having it fixed would not cost much. Could even be worth having all the green caps swapped for some higher grade ones whilst at it as they will go eventually.

[deanovw]

Thanks krazy_olie, I have an excellent repair chap near me so I may have him take a look. I will post the results if I do.

[quote name='krazy_olie' timestamp='1331762541' post='1578636']
Deanow i would suspect yours has developed a similar issue, I.ll let you know if my suspicions are right, if they are having it fixed would not cost much. Could even be worth having all the green caps swapped for some higher grade ones whilst at it as they will go eventually.
[/quote]

[SisterAbdullahX]

Oooh! I never did do that review, did I?

Well, I've had it for 8 months now and these are my findings;

The journey from the car to the gig is now done in one trip, bass in gig bag over shoulder, suit bag and bass stand in left hand, amp in right hand.

Never struggled for volume on any of the gigs (mainly weddings, but some larger stage/louder shows with 5 piece band). never had the master past 10 o' clock. Strangely, the power amp clip light does seem to come on at this volume but never heard a hint of distortion and never had to go any louder.

Sounds good to my ears, sometimes have to dial out a mid hump that can approach boxiness in some rooms, but that is easily done with the graphic.

EQ is fine! No more complicated than it need be.

Handles the low B on my Pentabuzz beautifully.

Never use the Vibe control. Can't say I've heard it turn it from a Shuttle to a Bassman, seems a little too contrived sounding for me so always have it turned off.

Yes, it does hiss but only annoying at bedroom levels (which is annoying!) but can't be heard at all at gig levels. Also, it has on one or two occasions had the volume drop off completely when set very low, but seemed to sort itself out with a quick turn of the master.

Overall, for the money I'd say 8 out of 10. If I'd had a bit more cash to spend at the time I probably would have gone for a Streamliner 900 and a second hand neo 2x12, but I didn't and am happy with how it's performed so far. Would like to try the head with another lightweight cab, maybe a Golight 410 or a neo 212.

As I said in one of the earlier posts, it arrived with slight damage to one corner of the cab and I was going to send it back. In the end I got a bit of a refund from Thomann.