Crate V30/V32 Palomino - MODS? Not V33, V18, V50 content.

I've been looking for some palomino mods myself, for my v16. There are tons for the v18/33/50, but almost none for the palominos. At the recomendation of the folks in the v-18 mod thread, this weekend I'll be switching the v1b 220k resistor to 105k. Aparently this makes a big difference in smoothing the gain in the v-series. I'll post the results. The v-32 should see similar results, so there's one possibility.

Edit: Almost a year later, and here's what I've changed: .001uf capacitor parallel to r40 and r42(the change at 42 made the biggest difference out of everything), and kept the parallel resistor in v1b. It's definitely smoothed out the gain a ton.

 

bump, singer in my band bought one of these and it could use some love to sound great. curious if people know of anything.

h.

 

these mods will work for the v32 or v30. V16 & v15 are probably the same, just not sure of the resistor labels.

Jumper r31 to take out the bass boost circuit. this will help tighten up the bottom end.

clip C38 to smooth out the gain, this will take out a lot of gain but sounds nice. perhaps make it switchable? ( that's what I did on my v30)

change the slope resistor to 56k. Makes the Tonestack controls work a little better and helps tighten the bass up.

 

saltysnail,
I'm curious to hear about the results of the plate resistor change on the v32/v30. I've been contemplating this for a while!

 

Looked high and low for the R31-couldnt find it! Clip R38? What exactly am I clipping out of the circuit? Which is the slope resistor? Bob

 

I know exactly what you mean. The 60 ohm resistor in mine(big honking resistor in the middle of the board) runs the tubes at about 13.5 watts. 1.5 watts higher than max dissapation. The amp eats tubes. Im using Sovtek EL84M's only because they seem to take it. From what Ive gathered a 100 ohm might cool it down closer to 12 watts and maybe not suck the mojo out of it. Bob

 

r13 is the slope resistor.


r31 is in between the mid and bass pots if i remember correctly. Its really close to the chassis, you may need to pull the chassis if your soldering iron has a larger tip.


Oops! It's C38, not R38 to smooth the gain. this will reduce the gain a bit though. That's why I made it switchable. i tend to run it with it disabled, and use a boost for extra gain if need be.

 

i'm contemplating doing this too. I just dont want to loose the mojo!

 

Im leaving mine alone. It just sounds great stock. OK the speaker and tubes arent stock but tubes arent a mod and if it was a head a speaker change wouldnt be either. Bob

 

here it is again from le horses mouf re V16 mod:

Jim, Dana,
The amp will benefit from the output transformer swap. It would also benefit some tube swaps, perhaps lower gain dual triodes like 12AT7, 12AY7, would help to control and "round" out the sound. Try them in the first 2 positions. That amp has a lot of gain, and you could toss some of it away. Then if it is still not "thick" enough, you could clip out C3. You may or may not need it depending on the type of pickup used, single or humbucker....
If you don’t want to change the tone too much you can clip out C38, that will lower the gain slightly and smooth out the tone without affecting the freqresp too much.
Speaker will also make a big difference. It is the final tone filter in the equation. Find the one with the freqresp that matches with the sound you are looking for. Vintage 30's are bright and nasty in the 1.6KHz range, I would not recommend one of these. A greenback is excellent, but maybe a little short on the bottom. Perhaps a Tone tubby might fatten it the best? I dunno, experiment.
Speaker - final freq response filter.
Tubes/circuit mods - gain, frequency response and amplifier to pick "feel"
Transformer - Dynamic response, clarity improvements, headroom, clipping characteristic.
Good luck and remember the warranty is void!!!!
Obeid


The 18 watt and 20 watt had the same size core and are not huge overspec OTs - I am betting that the 20 watt from Mercury would sound different than our 18 watt - but part of what makes those things different is not power increase or frequency response in the lower bands. The biggest difference in the high dollar repros that I have seen is an intentional imbalance in the output section that changes the distortion characteristic. When we were doing the Gibson stuff I changed the OT in the GA15RV from a Drake to the Heyboer that we still sell and there was a 10 - 15% increase in overall volume and it didn't turn it into a brash in your face sound - which would indicate that all the power was being increased in the upper bands. It was very smooth. My opinion is that unless you are making a 20 watt clone and looking for a very particular distortion characteristic the MM is unnecessary. The 18W we sell would be just as smooth and deliver just as much power and the GA15RV will deliver a very good sound at a very low price. If having the larger core size is part of your requirement then the 18W is probably for you - but I will tell you that I have built several amps for myself 18 watts and just 2 el84 output amps that I used the GA15RV in and was very happy with the results.
I guess I should add some background so you know where my opinion comes from. I was an independent tech for 10 years before I bought Mojo (7 years ago) and serviced most of the center of NC - since then I have been heavily involved in running our manufacturing which has built a couple 1000 amps over the last 4 years. While I usually do not get into "pinnacle of tone" conversations because it can be so subjective , I have tested enough amps that bad sound makes me uncomfortable so I usually have fairly strong opinions about what is good - but from a pragmatic point of view.

Andy Turner
Mojo Musical Supply
513 S. Dudley St
Burgaw, NC 28425
tel 800-927-6656
Tel 910-259-7291
Fax 910-259-7292
www.mojotone.com

*Important*
Please copy all text from our thread into any replies so I don't loose track of important info - some people don't seem to have thier email setup to do this. This is a generic message and is not targeted towards anyone in particular so please don't take offense.



Thanks for contacting me at Mercury Magnetics.

We can offer you a few different choices when it comes to an upgrade OT for your Crate amp. The ToneClone O20JM-L is the first one that comes to mind. This OT is cloned from the early Marshall 20 watt amp. It also used two EL84 tubes. It has 4-8-16 ohm secondary taps so it can be used with just about any speaker configuration. This is a real winner as an output transformer. All of my customers that have used this OT have commented about the wonderful tonality it brings to the amp.

The next OT that I can suggest for you is the ToneClone VXO-15A-LM. This OT is cloned from the vintage Vox AC15 amp that also used two EL84 tubes. It also has 4-8-16 ohm taps and it is regarded as one of the finest outputs available.

Either one of these OT's suggested above will be a HUGE tonal upgrade over the stock OT from the Crate amp. We have other options available to you. If you would like more suggestions, please give me a call and I'll be happy to help you over the phone.

Installing an output transformer is not too difficult but the OT's I've suggested may have more secondary taps than your stock OT and this may require you to hook up an impedance selector switch. I'm not sure because I am not that familiar with your Crate amp.

Best regards,

Paul Patronete
Mercury Magnetics
818-998-7791

 

70% is traditional for fixed bias amps and a tad hot for them IMO (anywhere from 55 to 70% ). Cathode biased amps like the V32 are meant to idle at 100% dissapation. The V32 idles at about 110% or so. Bob

 

Yes a 12AY7 works nicely in the V2 if your after less pre amp gain. Better than 5751 even.Bob

 

Excellent stuff. I've been looking to improve my V1512 a little bit and haven't been able to find any information on mods other than changing the tubes and speaker. I'll definitely look into the output transformer thing and post further if I make that change.

 

I changed the v1b resistor to 100k, and I've got to say... don't do it. It sounds better stock and the gain knob is much less responsive with the mod. I already switched it back.

 

I decided not to mess with success. Yeah it runs over dissapation but the price is only wearing out tubes faster. If I want to actually cool it down a bit I'll need to put a fan in it. It will still physically run hot even at a slightly lower dissapation-thats the nature of the design IMO.
Recently I suspected my G12K-85 of VC rub so I swapped in my little used G12T-75. I must say Im impressed once again with this combination. The G12T-75 has a subdued high end and tames fizz nicely like the G12K-85. Yeah its got that slightly "scooped" upper mid thing but it actually works pretty well . No money for new speakers at the moment so Im keeping it in for now and seeing if I bond with it more.
As for modding the pre amp section Ive must have been crazy for comtemplating that. Its fine just the way it is! Bob