Hafler T-2 tube Pre-amp review/experiment.

[fauxsuper]

These have been around since the late 80's and I don't know when hey stopped making them. I bought one off of E-bay for a little over $70. I've read reviews of it where the clean channel is described as sort of bland and the drive channel as being high gain.

I have an amp that is loosely based on a tweed deluxe. It has a tone control of sorts, but it doesn't have an extensive range. I bought the pre-amp as a way to give it tone controls and maybe a little tube overdrive. The pre-amp come with 2 12ax7's. One for each channel. I was betting I could tame the drive channel by inserting a pre-amp tube with a lower gain factor.

When the amp came I decided that with a little knob twiddling I could make the clean channel output signal pretty close to the guitar straight into the amp. The clean channel has two knobs, one "bright" and he other a level control. You can toggle between the two channels with a footswitch.

The drive channel has gain, presence and level. The two share a 2 band EQ section. As most reviews I've read stated the drive channel has nearly insane amounts of gain, and would seem to have a radical onset of distortion. Not too useful for those who live in the area between slight overdrive and all out fuzz.

I opened the pre-amp and was amazed at all the circuitry on the printed circuit board. The chassis is a single space 19" rack about about six inches deep and the circuit board is nearly full of stuff. Not a simple circuit by any means.

As I suspected, putting a 12at7 in the drive channel tamed it considerably. There is an area where you can go between distortion and clean with the volume pot on your guitar now. You can also find a setting that works when switching between he two channels: it's a little tricky, but patience is eventually rewarded. I find it a little bright at full volume with a single coil bridge pickup, but backing off the tone control a mite helps a little. Humbuckers are just fine.

Both channels seems to have sufficient room to try tubes with a little less output, so I'm thinking a 12au7 in the clean channel with a 12at7 in the drive channel might just be the ticket. What is nice is that the pre-amp seems to integrate well with my amp, sounding very organic.

At any rate, you do find these fairly regularly at reasonable prices on E-bay, so they might be worth a look. I'll keep you posted as I experiment further.