I bought one of these after I sold my perfectly modified Epiphone Valve Junior with the help of 18watt members and 300+ pages of chit-chat. I get bored rather easy, and was going to go with the Valve Junior again (I sold it to see if I could get the combo and do similar things, but the price increase told me that there were greener pastures) as a platform, but decided to try out the Crate V5 since it was a combo not much bigger than the VJ. I like 10 inch speakers, I liked the looks of the amp, and thought that even if I have to replace everything and even make up a tagboard for it, it would still be cool. I also was hearing what others have been saying about the Crate and when I got it, surprise! I agreed that there was something amiss and decided that to just accept it and give it back would be like throwing in the towel. I knew that it could be better and I systematically worked on each section to see how my $100 initial investment could be improved on.
Speaker was pulled first. Weighing about a pound and with a tiny magnet, tiny voice coil, stiff suspension and a plastic (!?) cone, I could tell just by tapping on it that this was a tone sucker and big part of the bass weakness. I figured that it could be used in an amplifier to take to the beach or other dirty, wet place. The chassis looked awfully close to the speaker magnet, and I didn't think I could get anything in there that would be decent.I measured the depth of other speakers that I had and found that I was wrong. There WAS room for a better speaker. I popped in a 50 watt Eminence 10 inch and it cleared the chassis. Hooked it up and fired it up- better tone and bass, but the amp was still shrill and unmusical.
Looking inside the amp on the circuitboard I saw of all horrors, an op amp!. OK, I know, you can get good sound out of op amps, but looking at the circuit with the volume control in the feedback loop in the second stage, was didn't sit right with me. After the op amp, the tube circuit was fairly conventional other than a quasi- parametric tone circuit between two tube sections of the 12AX7. But looking at the output of the second triode section, I could see that 90% of the signal was dumped just before it got to the grid of the power tube. I guess that is why they needed the op amp in there- to make up for lost gain in the output tube's voltage divider at the grid. (Why?)
So what I did is to cut some traces and add some jumpers to make it an all tube amp. After the input resistors (1.5Kohm and 1 Meg) I cut that trace going to the input of the op amp and sent it straight to the first tube grid and cut away any other parts that were there that might have influence. I decided that the tone control was not a bad thing, just different- and I left it as is. Since I now had a 250Kohm volume pot out of the circuit, I put that between the tone circuits and the grid to the second triode in place of the attenuation scheme that was there and to maintain grid to ground loading and control. I cut the traces around the volume pot and ran jumpers to the appropriate places (the pot connects to the output of the tone circuit, the two lower resistors were cut out, and the other end of the pot was run to ground. The wiper fed the second triode's grid.
I checked for stability (good) output power-6.1 watts at clipping; up to 9 watts fully overdriven. and residual noise 7mV rms (from the power supply). The tone control can be more easily understood when you use a fuzz pedal or other distortion box into the input. It changes the midrange tone in weird ways, but it is better than just a treble cut, since your guitar already has that. Put your metal pedal in front of it and see how much range of tones you can get from it.
Clean on this amp is very good. You can have your amp set at 12 noon, and your guitar all the way up and it will be clean until you start hitting notes hard (or if you have hotter pickups, perhaps a bit sooner. Alternately, you can turn the amp all the way up and still get clean tones with the guitar just cracked open and swell into the realm of output tube distortion. It is very easy on the ears and very pedal friendly. Using external EQ helps you get the tone that you need/want from various axes.
I had ordered a new transformer for this amp (EDCOR 15 watt- the same one I used in my Valve Junior with great success- $20.64 plus $6.37 shipping), but I am happy enough with it the way it is (the output transformer in the Crate is much bigger than the Valve Juniors'- 10 watts instead of 5). I get deep tone from only a 10 inch speaker and I have to be careful not to use the neck pickup too much- it rattles the pictures and things on the wall in the living room. That transformer is going to have to wait for my 6550 single-ended project. One big output tube- should be cool and about 10 watts!
If you just want to add lots of gain easily and just get your feet wet in trying things, pull out resistor R27 (10K) and short out R 15 (100K) and that will get all the lost voltage (the sound) to the output tube and not lost in those 2 resistors. That way you still have the 2-stage op amp pre driver and it might be more of what you want (if more is better- like metal tone). I wanted pure tube and I got it with only an Exacto knife, 3 pieces of short wire, and some cutters and soldering rig, I didn't need to replace the output transformer, or add any parts in any location. Other than replacing the speaker, that was my only expense. I got the 50 watt Eminence for $12.00 each when I bought 4 from a music outlet store on line. I have used those speakers in amps from this 5 watt one to a stereo 15 watt rig and for a 40 watt combo as well. Tubes are all stock. Surely a better transformer and/or tubes will make a difference, but I got night and day difference with these simple mods. Sounds great for little $$$. If you want, and you can pull the board and replace it yourself, I can mod it for anyone for $40.00 plus shipping (which would be nominal in a Priority mail flat rate envelope ($5.00). There is hope for Crate V5 to become the 'next big thing in small amps.

Deafelectromark (alias manoteal)