New to tube preamps

[guitarkirkster]

I purchased a Hafler T2 preamp. It is the earlier version which doesn't have the extra gain pull on the drive knob. It was lacking some drive so I replaced the RCA tubes with High Gain JJ/Tesla ECC08's and the drive increased a bunch.

I still want more drive/gain for shredding. How can this be achieved?

I am kind of new to tube preamps and have pretty much always been solid state.

Should I use a pedal in front or is there some type of inexpensive mod that can be done?

Thanks.

[Tubis]

Maybe put this one in front. http://www.jimdunlop.com/index.php?p...p_and_e_detail
For shredding you need tight bas and the extra signal input needs a bit of treble cut. This pedal will give a lot of signal boost into the preamp and you can trim the frequencies perfectly. If you have a schematic of the preamp i could tell you what needs to be done in form of mod on it but a pedal is a good way to go.

[guitarkirkster]

I will have to go to my local music shop and give one of those a try. Thanks for the info.

I have attached the schematics like you said if you want to take a look. Thanks.

[Tubis]

Strange design. First putting a transformerload 12ax7.
To simulate output distortion i guess?
And thene have a diod clipping distortion stage that ruins the tube sound after it.
It´s worse than Marshalls JMP-1 ripoff

Well. Replacing the 100k r4 resistor with a 220k will get some higher signal levels into the distortion stages.
Watch out for dangerous high voltages.

[teemuk]

And thene have a diod clipping distortion stage that ruins the tube sound after it.
It´s worse than Marshalls JMP-1 ripoff

The habit of seeing any addition of solid-state components as an instant issue of tone degradation can blind from the fact that the diodes are in series with a 220-pF capacitor. Therefore they won’t contribute much clipping, except at quite high frequencies. And what comes to comparison to Marshall JMP-1, I fail to see any significant similarity aside the fact that both preamps are hybrids. I hope that grin emoticon meant that you were kidding.

What comes to modifying the circuit for more gain I see plenty of possibilities for tweaking. There are too many of them to actually start listing each and everyone here, though. Besides increasing the stage gains (such as the gain of the first opamp stage or the tube stages following it) look for resistive dividers that attenuate the signal. There seems to be plenty of them.

Personally, I would try a pedal or even resort to getting a different preamp altogether. One can do several modifications but there likely isn’t a mod that would instantly change the whole character of this preamp. Maybe it’s just not the right one for you.

[guitarkirkster]

Thanks for the help guys. I might start looking for something different to shred with.

I will say, this preamp does get some good blues tones that are fun to play with.

Any suggestions for a good thrash/speed metal preamp that is in a good budget? Could be tube or solid state.

[guitarkirkster]

Has anyone ever heard of or used a JACKSON JX-3 PREAMP? I know where to get one used and the reviews on Harmony-Central seem to praise its sound for metal. Any clues? It is supposed to be a tube preamp.

[Chuck_Farlee]

Originally Posted by guitarkirkster

Thanks for the help guys. I might start looking for something different to shred with.

I will say, this preamp does get some good blues tones that are fun to play with.

Any suggestions for a good thrash/speed metal preamp that is in a good budget? Could be tube or solid state.

I'd suggest checking out the Hafler T3, the hot channel is great for shredding. Aslo check out the the ADA MP-2 and the Soho Acoustics QTR-1 preamp if you get a chance. All three have tubes in them.

chuck

[OverDriven]

Originally Posted by guitarkirkster

Thanks for the help guys. I might start looking for something different to shred with.

I will say, this preamp does get some good blues tones that are fun to play with.

Any suggestions for a good thrash/speed metal preamp that is in a good budget? Could be tube or solid state.

Mesa Studio Preamp if you want the best lead tone Mesa has ever created. It sounds absolutely amazing. What are you using for a power amp?

[separanets]

Appologize to raise this thread again.

I need to replace a J174 transistor (Q7 in the cirquit), but they told me they aren't import these transistors any more. So I wonder what could be a replacement for that J174. Can you suggest me alternatives please?

Thanks.

[Tubis]

Any p channel jfet with the same or better valuse will do.
Datasheet link: http://www.datasheetcatalog.com/data...7/4/J174.shtml

[separanets]

Originally Posted by Tubis

Any p channel jfet with the same or better valuse will do.
Datasheet link: http://www.datasheetcatalog.com/data...7/4/J174.shtml

So the J176 will be suitable, right? Ok, thank you!