Blackstar Artisan 15 - warmer tone

[Bernd]

Hi everybody,

I haven't been here since a long time ( I was playing mainly acoustics...)
I bought a Blackstar Artisan 15 combo about 6 months ago. Great dynamic response of the amp, what I miss is a warmer tone. So I tried a lot: changing preamp tubes which gave more mids but spoiled the tone so I put back the originals, I tried different speakers (came originally with a Celestion G12M 15W), I tried a vintage 30 which gives a fatter tone but a little too aggressive, Greenback 25W is what I use now.

Is there any experience out there with this amp? To my ears the amp is to harsh and trebly sounding (clean and overdriven mode), this can be heard on various youtube videos (not the company's video). I had even contacted the manufacturer but the answer I got was to roll down the treble pot on my strat, any further discussions were not possible. Any experience about the power tubes - maybe too cold biased? (The amp has fixed bias)

Any suggestions are welcome.

Bernd

[ModMan]

If you were trying different speakers could it be you are finding the 12 to beamy you could look at the weber beam blockers to help diffuse the highs or just use gaff on the inside of the baffle?
Otherwise you would have to venture inside the amp and possibly lower some cap values that effect treble depending on the circuit.

[guitarmike2107]

I suspect those amps have a tight bass response to ensure the power stage doesn’t fart out when driven hard.
This ends up making the amp more “thrusting” at lower settings
See if you can get hold of a schematic, that would make figuring out any mods easier.
Or get us some high resolution shots to see what’s inside…

[J M Fahey]

Please post a picture of the control panel or a link to its user manual and tell us your settings.
A schematic would be even better.

[Bernd]

Thank you guys for your thoughts,

I don't have the schematics of this amp, I once opened the amp to see the main things but it is hard to follow by eye all those wires inside.
Yes, the amp has a tight bass response. I forgot to mention that I connect my guitars always directly to the amp,no effects in between.
I made another test and played the amp through my old 4x12 Marshall Greenbacks cab from 1969 and suddenly there was a real sweet tone coming out. I have the impression that this amp is simply too new it should be 40 years older to sound great ;-)
I just looked at he Weber beam blocker - this is a nice idea, I will try something like this or will try to get a real old speaker.

Bernd

[ThermionicScott]

Let's see -- 2xEL84 output, EF86 channel, Celestion Blue... I'm guessing they used the AC15 as a starting point for this amp, which will give a tight and bright sound. From their description, the Tone control sounds like more than just a treble-cut. Maybe it's more like a Big Muff control, where it will actually roll off low end as you turn it up -- that could be the source of your discontent.

Plugging into a closed-back cab will definitely give a darker, thumpier sound. I've got an old 2x15" Bassman 70 cab that is too inefficient and underpowered to work for bass, but guitar amps instantly take on more of a Marshall vibe when plugged in.

At any rate, I know I wouldn't be able to hold myself back from tinkering if I bought one of these amps. With that turretboard construction, it practically begs for it!

- Scott

[beano4ever]

Hi Guys,
New poster here. Like the OP I also have the Artisan 15 combo and am experiencing the exact same problem.. I really want to like this amp because it has all the qualities of a great amp. It is very dynamic/ touch sensitive, responds great to pick attack, cleans up nice, and its built like a tank. It has everything it needs to be a classic imo but it is just so darn bright!!!

Mine has the UK made Celestion G12M speaker and even with the tone knob of the amp on 0 it still seems bright if I am using the bridge pickup on my Les Paul. I roll the tone knob of my guitar way down as well but if I lower it too much it starts to become muddy and I loose definition. Here is a link to a bigger image of the tag board but its not close enough to tell the values.
http://www.performing-musician.com/p...15tagboard.jpg

I have owned a couple of 18 watt Marshalls and in many ways this is a very similar amp, except for the extreme brightness. Anyway, I would like to keep the amp but if I cant find a way to warm it up then I will probably have to get rid of it and that will be a shame because I really want to like it.

[guitarmike2107]

Well it would be easy enough to add some bass to this amp, but too much bass is not a good thing on these types of amps as they fart out quickly when cranked,
Would you do the job yourself, if so crack it open and get the actual values used. Otherwise find an amp tech that is prepared to work on it for you.

It might be that the volume control has a big bright capacitor across is or that the coupling cap off the first stage is dumping loads of bass, but we don’t know because we don’t have the components values or schematic

[txstrat]

...it is just so darn bright!!!

To pick up on the beamblocker idea.
Two stripes of gaffa tape side by side on the grille cloth in front of the speaker cone can soften the highs like a beam blocker.
SRV did so with his MusicMan amps.
It might help.

[J M Fahey]

Or you might go "beyond" the problem, bypass it.
What you seem to find objectionable is "the beam" , which really does exist; it's a huge peak in highs typical of all guitar speakers, caused not by an increase in efficiency at those frequencies (far from it) but because all power concentrates in a narrow ... beam (duh!).
One aftermarket solution is to put sound absorbing materials just in front of the speaker center dome, in the path of said beam.
Good, it works, sort of.
You are not *really* making the speaker mellower, just less harsh (which is not exactly the same).
1) Why don't you jump the fence and go for a speaker which does not have such peak?
I suggest you try your amp with a flatter, PA type speaker, such as Eminence "Greek letter" series (Alphas/Betas/Gammas/etc.)
They are loved by many Jazz players because they are *warm* from the beginning.
Search and pick the highest efficiency one you can afford; after all you are not in a Jazz band.
2) The "trivial solution": if still

To my ears the amp is to harsh and trebly sounding (clean and overdriven mode),

which are harsh words (no pun intended) , consider trying other amps you may like better.
Anyway you choose, good luck.

[beano4ever]

Thanks a lot for the the ideas guys. I wish I could get my hands on the schematics and post them but for whatever reason Blackstar doesn't or wont release schematics of their amps. I think I will start with the trying the gaffa tape and or one of these beam blockers and then work from there. If that isn't working then I will try the eminence speaker suggestion and I have a local tech here that can open it up and change some caps if need be.

I also will try to maybe find some darker sounding tubes. I have a couple old Mullard EL84s that may warm it up and I have read that RFT pre amp tubes sound a bit darker. It has EH tubes in it now,which is what came from the factory.

Again thanks a lot for the suggestions guys.

[Bernd]

Hi Beano,

one of the keys is the speaker in my opinion. I feel that the G12M 15W is the worst sounding speaker in this amp - please see my comments in my first posting regarding the different speakers. I don't want to say that this is speaker is generally bad - I once connected my old 50W Marshall to it and it sounded great - but not with the Blackstar. So changing a speaker is a very easy thing. Changing power tubes needs rebiasing and this amp has a fixed bias setting which does not make things easier. I also noticed a slightly smoother tone by using a longer speaker cord.

There may be a capacitor enhancing the highs, this might be one point to start as it was already said. I also thought of putting the 2 channels in series and see what comes out - one day when I have the time to do it.

Bernd

[beano4ever]

Hi Beano,

one of the keys is the speaker in my opinion. I feel that the G12M 15W is the worst sounding speaker in this amp - please see my comments in my first posting regarding the different speakers. I don't want to say that this is speaker is generally bad - I once connected my old 50W Marshall to it and it sounded great - but not with the Blackstar. So changing a speaker is a very easy thing. Changing power tubes needs rebiasing and this amp has a fixed bias setting which does not make things easier. I also noticed a slightly smoother tone by using a longer speaker cord.

There may be a capacitor enhancing the highs, this might be one point to start as it was already said. I also thought of putting the 2 channels in series and see what comes out - one day when I have the time to do it.

Bernd

Yea I agree that a speaker swap would be the easiest and most direct solution and after doing a bit of research I have decided to get a Eminance Cannibis Rex. Everyone seems to be in agreement that this is a great speaker to use for taming an overly bright amps and its not expensive either. I am pretty sure that the artisan is a cathode based amp so it wouldnt need rebiasing but regardless tube swaps can be hit or miss. I think this speaker change should do the trick.

[Bernd]

Hi Beano,

by the way, what is your opinion about the Marshall 18W reissue compared to the Blackstar Artsian 15? So far I had no opportunity to try this amp.



Bernd

[beano4ever]

In comparing the two I would say the Artisan has much better and usable cleans. Granted it doesnt have a lot of headroom but on the 12ax7 side their is decent amount but on either channel the cleans sound good to me. On the other hand the Marshall doesnt really clean up well at all. For the little amount of cleans it does have it sounds okay. When overdriven, the Marsall sounds sweeter and warmer to my ears. As you know the high end on the Artisan can be bright and a bit harsh. Even though its bright, it never sounds thin. Its fat and bright and will rip your head off if your not careful, but not so with the Marshall. It retains its warmth and smoothness.

To sumerise I would say the Artisan is the more flexible out of the 2. It has the 2 channels of 12ax7 & ef86 which can also be jumped and mixed, has the 5/15 watt push pull/ single ended mode and has some very usuable cleans. The OD tones also sound pretty good and if I can just get the brightness/harshness issue worked out with the speaker swap then it should be great.
The Marshall has the tremolo channel but I never used it, has marginal cleans, but a very sweet and great sounding OD right out of the box, no mods needed.