Bass Gear Review

Reviewer	Ron Kimball
Experience	20
Email	Ron@Aspinock.com
Review date	May 16 2003
Manufacturer	Tube Works
Model	RT904
Price	62
Item owned for	1-6 months

Dimensions	Single Rackspace, 6"(?) deep
Weight	5 (?) lbs
EQ	Low, Mid, High, Contour
Other	Instrument and Line in, Instrument and Line out, Footswitch Jacks for
	Boost and Bypass.

This unit is normally considered a rack effects processor but has an instrument level input enabling it to be used as a preamp. My unit came to me with the fairly common mod of moving the instrument level input to the front panel. I modded it for my tastes by replacing the 12AX7 with a lower gain N.O.S. US made 12AU7 for smoother overdrive, and I paralleled the .047uf Midrange capacitor (connected to the middle terminal of the Midrange control) with another .047uf capacitor to move the midrange control down from it's normal 500-800Hz to 250-400Hz (I'm told the center frequency moves through that range depending on where the High control is set?). For Bass, the Contour (pre-overdrive Bass cut) is left all the way up, Bias on zero, Mid on zero (leaving a hole for the Kick drum), Hi and Lo on 5. Bypass is never used and Boost can be used for leads if you like. I have two of these units, both bought from eBay. The first was mounted in a SKB X-Rack shallow depth 3 space rack case with an old Traynor 120 watt PA amp I got for $50 off of ebay. Driving a vintage Ampeg B25B 2x15" cab (rated at 120watts and rewired from 16 to 4 ohms) I get an incredible vintage Ampeg/Tube sound at a volume those of you who are used to inefficient 4x10 cabs wouldn't believe! The second one I just put in a similar but smaller SKB X-Rack shallow depth 2 space rack case as I found a Tube Works single rackspace stereo MosValve amp for $51 on eBay (just had dirty pots, 5 minute fix!). This amp will put out almost as much watts as the Traynor into 4 ohms on one channel and drives my little Gollehon 1x15" cab I got for $20 off of eBay at 160 watts bridged. It uses Mosfets in the output so when overdriven it sounds very much like a tube amp - volume more like a 300 watt solid state amp. The preamp and amp look like a matched set, too!

Construction	100%
(Steel Chassis. meant for rack mount.)
Clarity	75%
(You want "Clarity" this ain't it. It is SUPPOSED to color your sound, Doh!)

Versatility	75%
(It has a "Sound", and it is either what you are looking for or not. You ain'
t gonna get that crappy modern "LA" sound from it...)
Customer Service	95%
(I asked for a schematic of this discontinued unit and they wouldn't give it t
o me, but I had explained what I wanted to change and they told me what capaci
tor to change!)
Value	100%
(I paid more than this for a used pedal version!)
Overall	100%
(With the mods I made it is perfect for me, YMMV.)