Star Amps Info Help Request.

[ToneChimera]

Hi;

I have the Gainstar 15 and am working to optimize it for my tone preferences. Mostly cleaning up muddiness and preserving chime.

I have had no luck searching the Star web site or the product manual for any contact info. Is Mark kind of reclusive? The info out there is mostly advertising.

My question is about the pre-amp valve layout. They are not identified on the amp. Looks like about 6 pre-amp tubes.

Results so far in optimizing the clean channel:

1a. A G12H30 helps to reduce the excess bass enough to make the change permanent.

1b. A Fuchs bigger cab 1x12 gives a tighter bass with deeper lows.

2. Hooking the amp to a 65 Amps 2x12 cab gave a shimmering and pulsing kind of high that was intoxicating. Done at SBG when they weren't looking. Too much bass for my room however. Excited room modes too much.

3. Turning the bass to zero still leaves enough bass but helps to reduce upper bass muddiness, esp with Fuchs cab.

I don't know if changing pre-amp tubes will help to reduce the last muddiness, but worth a try. And I have some non-JJ Tesla EL-84s to try once a Bias Rite arrives. Maybe a thinner 12Ax7 would help some.

The distortion on the clean channel has nice potential.

For the gain channel, I haven't done much. Interesting but not inspiring. Would try an OD pedal that drives highs as a first choice.

Probably not too many out there have experience with the Star, but where is Mark S?

Thanks.
TC

 

[drbob1]

He was at Arlingtn on Saturday. Nice guy, we talked a bit about old times.

 

[Luke V]

Don't know about Gainstar but I would try different tubes, input and output. I spent several hours this weekend with my Orange amp swapping tubes. Different tubes in different sockets make a big difference. Tubes are cheap, get a few different brands of each type and let the fun begin. I even found that different tube combinations worked better with different speakers.
Good Luck

 

[ToneChimera]

Thanks

Tried RCA Blackplate 12Ax7s at the paired preamp location. I think that is the clean grouping. Will keep 'em there. Didn't try the triplet group of preamp tubes.

Now I just have to find out if the EL 84s are cathode or fixed bias. Don't know yet what to look for.

A G12H30 cleaned up some of the lower muddiness in the cab. But I can moderate the muddiness by playing closer to the bridge also. The mud does add some nice thickness to power chords tho. Less desireable for full barr chords. I run the bass btn 0-1 clean most of the time. Playing style, of course.

TC

 

[Timster]

I haven't noticed any mud on my 15, but I have to admit, I don't stay in the clean channel very much. The gain channel is awesome in my opinion. I like a lot of gain so I ususally end up diming the gain and turning the master up to 12-3:00 for some amazing, grinding marshallesque-dumble-like high gain grind. If anything, with these settings, I need to turn up the bass a bit to 1 or 2:00

How do you have the amp set up in the clean channel? What guitars are you using? Pickups? What type of music do you play? I'll have a chance over the weekend to turn up my amp, so I'll look and see if it muddies up at higher volume.

As for tubes, I think the 2 preamp tubes in the middle of the amp are the effects loop and the phase inverter. The 3 in the back (closest to the front of the amp) are the clean channel, tone, and gain channel preamp tubes. Also, the amp is cathode biased, so you can put in a new set of tubes without biasing.

I have 2 mullards in the power section, and telefunken ribbed plates loaded for the preamp tubes. They made a nice difference from the stock configuration.

Hope this helps.

 

[ToneChimera]

Hi Timster;

Have been playing w SCs mostly now. Strats. I really don't dime the clean, usually running 9-10 and using the guitar volume. Really like the OD on the clean side myself. Treble to 11 and bass 0-1 gives the best articulated barr chords for me. Brilliance is off.

When I say mud, I would clarify and state One would, on the average, need to listen carefully to discern. Many could disagree with me happily. Many would take advantage of it also.

I have some Non-JJ Tesla EL 84 I can try this wekend, and I will sub out the preamp tubes near the front of the cab.

Tried a Fuchs 1x12 cab and a 65 Amps 2x12 stock with nice results. Fuchs gives a punchy tight bass and the 65 shimmering cleans.

Thanks
TC

 

[dankayaker]

I have not noticed any muddyness with my two main guitars. To me, this small amp sounds huge in a band configuration, but I would love to have a nice 2x12 to make it sound bigger.

I'd also love to talk with Mark about this amp . . .and the potential for having the FX loop on the clean channel also. The website is pretty useless. . .I would think he'd want more info out there . . but I don't see it.

probably the finest (relatively unknown) amp out there IMO.

 

[Curly]

Although I saw & heard the Gainstars at the L A Amp Show, I didn't get a chance to play them, but I always like to see what Mark's up to.

I'll just say that running the bass so low seems a bit odd, and I would expect you'd be missing some fullness.

Also, I don't remember hearing anyone say a G12H helped reduce bass response - usually something closer to the opposite is true, since the G12H is known for its bass response.

 

[dankayaker]

Yeh,
its been my experience that G12H's really emphasise the lows . . . .I''d like to hear a Blue in this amp.

 

[ToneChimera]

Hi;

A G12H30 helps to reduce the excess bass enough to make the change permanent." TC

I am happy with the amount of bass with this spkr (G12H30). I think it is tighter now. No less deep. But I lost some of the upper bass coloration/ excess that I heard before. Barr choirds come out more unto themselves, more distinct. But I think I am half way there.

To be honest, I don't know if this is a tonal coloration of these frequencies, or a big hump in these frequencies. I should move it around in the room and raise the height to see if that affects the frequency area I am working with. I now don't think the Star cab is the cause.

The Fuchs cab really allows great bass depth and tightness. Ported and a bigger box than the usual 1x12. Still some lack of focus/ mud remain in the upper bass.

Thanks
TC

 

[stekks]

How are the EL84 doing in that amp? I'd order a set of EL84 that has the lowest idle-current from a company that tests/matches/burns-in the tubes (some call it vintage Vox-spec tubes). If the idle-current is too high, it may cause some 'muddiness'.

 

[ToneChimera]

Thanks.

More tubes from Mike.

TC