Crate V5 mods... anyone?

[Tarin]

Yep, i'm one of those who fell for the Crate V-Series blowout sale, at first i bought the V-18, and considered it a good amp, great for the price... sold it after a great offer made to me.
Went back to MF only to find out they were out of stock (also in GC, Sameday, Samash and everywhere).
Made my homework on the V5, and althought it had bad reviews i went for it thinking "how bad could it be" and "even if it's that bad, somebody will come out with mods for it".

Well, the amp sounds pretty bad (not as bad as the reviews claim, once the cheapo speaker breaks in you get decent tones, that and an EQ pedal), and as of now nobody has come out with a mod for it.

I got in touch with an Ebay seller who has one "Modded Crate V5" on sale but he asks 230 bucks for it and doesn't sell any mod kit for it (he claims modding this amp consists on almost building an entire new circuit).

I'm sure i'm not the only one stuck with a V5 waiting for mods... any help?

[Andy]

best way to mod one? sledgehammer.

[Tarin]

Sledgehammer... not a good idea, the cab in itself is alright.

[tunghaichuan***]

Have you ever worked on tube amps before? Do you have a DMM? Do you have a schematic for the amp?

I believe the V5 is the same amp as the VC-508, but with different cosmetics.

I've never seen the inside of one, so it may be hard to mod if there are SMDs on the PCB.

tung

[Tarin]

Nop, not a licensed tech or anything... i consider myself a good tinkerer and good with a soldering iron, but i could never come up with the slightest idea on how to mod a tube amp.
That's why i'm waiting for some mod-kit to come up (with instructions), that i can manage. BTW, i'm aware of the dangers involved in tube amps, and know the right proceedures for a proper drain.

Schematics i don't have but i'll start working on getting those (never dealt with Crate people).

As of now, i only have some pics of the amp's board (if that gives any help).

[Tarin]

A few more pic's of the Crate V5...


Sovtek tubes...


And here, the 99 dollar cab and crappy speaker...

[tunghaichuan***]

The good news is that it looks like there are no SMDs on the board.

One thing I would check is the bias. If the schematic I have is correct, the cathode bias resistor is only 100 ohms. It seems like it should be bigger.

You will want to check the plate voltage as well.

What are you trying to accomplish by modding your amp?

tung

[Tarin]

The amp lacks of bass tones, and the overdirve is kinda fuzzy. the volume range jumps drastically when dialed between 6-7... cleans are ok.

The tone knob is really wierd... seems to be a -10/0/10 kinda knob where turning it from one end to the other (0 to 10) the tone at 0 seems be down, then go up at the middle (5) then down again when reached 10 (dunno if i explained myself).

I've read a few other reviews were changing the speaker and tubes helped for some, but others claim that not even that helped (i don't have extra speakers nor tubes to try this out).

So basically the mods consist in providing some bass to the amp and making the tone knob work correctly.

[tunghaichuan***]

Just to make sure I'm looking at the same schematic, what value do you have for R17? On my schematic, it is a 100 ohm, 5 watt resistor.

The circuit should have plenty of bass. I would guess that it is a combination of the 10" speaker and a small output transformer. I wouldn't know what to recommend for a replacement, it depends on how much real estate is on the chassis, and how the OT is connected into the circuit.

The volume control is kind of weird. On my schematic, it is a 10k linear pot. On most circuits this control is 470k to 1 meg ohms and would be an audio/log pot.

The tone control looks like a modified Baxandall to me, but I could be wrong. It definitely isn't the treble cut tweed type that I'm familiar with.

The input gain stages is a cascaded opamp. A TL072. Any of the replacements will give you slightly differing results. I would pull the stock opamp and put in a socket so you can swap them out easy. I believe the TL072 is pin-compatible with the Tube Screamer types. You might even want to spring for a spendy Burr-Brown type.

tung

The amp lacks of bass tones, and the overdirve is kinda fuzzy. the volume range jumps drastically when dialed between 6-7... cleans are ok.

The tone knob is really wierd... seems to be a -10/0/10 kinda knob where turning it from one end to the other (0 to 10) the tone at 0 seems be down, then go up at the middle (5) then down again when reached 10 (dunno if i explained myself).

I've read a few other reviews were changing the speaker and tubes helped for some, but others claim that not even that helped (i don't have extra speakers nor tubes to try this out).

So basically the mods consist in providing some bass to the amp and making the tone knob work correctly.

[Tarin]

I got in touch with LOUD Technologies and they kindly sent me the schematics, PCB assembly and parts chart promptly. (i can email them if needed).
Tung, i really appreciate your interest on helping out making this little amp something worth the 99 bucks...

R17 is: WR 330 5% 5W

As for the volume pot, it's a 250K 05A 15mm single unit.
Tone pot 250KB 15mm single unit.
R12 reads 43K .25W

[sumitomo]

best way to mod one? sledgehammer.

I'm with Andy whip out that 5 lbs. precision adjuster and have at her.Sumi

[Tarin]

Tung, i'll post your email comments (for anyone following this thread):

Looking at the schematic, it looks a lot like the VC-508. The V5 isprobably an update of the older amp with a larger speaker and someupgraded parts values. Do you want more bass in the clean sound or distorted sound? You couldbump up C1 to 22uF/50v, but it might make the amp sound flubby/farty. Other areas to look at would be replacing the speaker with a better oneand replacing the output transformer with a better one.

To me, cleans sound ok... i'm using humbuckers so messing with the tone knob on my guitar get's me some good tones on it.
While overdriven the amps sounds ice-picking thin, i use a multieffect pedal, Digitech RP250 and all my distortion based presets sound like that to (not thru my Vox Pathfinder 15R).

The speaker replacement issue is a bit confusing... the only spare speaker i could use is the 8" stock one on my Vox 15R and as a said erlier on this thread, lots of reviews claim that swapping the speakers and tubes helped, and others claimed it didn't... so, i'll try using the smaller speaker i have at hand (not a big step forward, but might help).

As for the OT, same issue... i had to buy one.

At first i thought i could get decent tones just by replacing resistrors and such (an inexpensive and fun way of modding) rather than swapping parts (no fun-labor factor there, and could be a bit expensive)... but i guess that drill goes: first swap stuff then mess with the board.

any recomendations on an inexpensive OT?... theres a lot of space in the cab.

[Tarin]

Now we have one question answered, there's a post on Youtube with a comparison of two V5's: one stock and one with a Celestion G-10 speaker on it.
On a side by side camparison you can tell that a speaker change helps a lot.

Video is posted by The Tone King... great reviews from him.
http://www.youtube.com/watch?v=na0mrc1QZoY

Take a look and tell me (us) what you think now that you can be able to listen to a stock V5.

Oops, +-100 bucks for a G10 speaker... ouch.
Any recomendations on a good not-so-expensive 10" speaker?

[Andy]

I heard a crate with the warehouse spkr greenback clone($69-green beret) in it and it made a world of difference.,,well worth the expense

edit* my bad, that was a 12"

[tunghaichuan***]

I heard a crate with the warehouse spkr greenback clone($69-green beret) in it and it made a world of difference.,,well worth the expense

edit* my bad, that was a 12"

Warehouse makes a 10" speaker as well:

http://warehousespeakers.com/products.php?cat=8

Probably better sounding than the stock speaker.

I really hate to recommend this one but for an inexpensive, good sounding OT, Edcor USA makes a decent one. I hate to recommend it because it comes with faston solder tabs. It looks identical to the one here:

http://www.diycustomamps.com/images/...chassis_57.jpg

These are inherently unsafe as there is exposed B+ outside the chassis, not a good idea. If you decide to use one of these, be very careful and insulate all the solder tabs. Don't touch the OT with the amp on. They're about $20US + shipping.

tung

[deafelectromark]

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)

[SuperSwede]

Hello Deafelectromark (alias manoteal) and welcome to the fret net.
You seem to like to write a lot, so why dont you write something about yourself in the fret players section?

[deafelectromark]

Hello Deafelectromark (alias manoteal) and welcome to the fret net.
You seem to like to write a lot, so why dont you write something about yourself in the fret players section?

Hi Super,
Yes I am new to the Fret. I have been a member of other sites, most notably 18 watt and now SEwatt. I have been selling on eBay for about 5 years now and I am a deaf musician. You can read my bio on eBay (deafelectromark) and if you tell me where to post a howdy here, I will do so.
I was drawn to this site when a friend in Mexico was having similar concerns with the poor quality sound from the Crate V5- an amp that I bought with the hopes of improving, since many people were also dissatisfied.
I have been doing electronics for over 40 years, got a Electronics technician certificate at trade school, taught eleactronics at that same school for a time, worked in high-end (read $$$$$) audio during the heyday of CD's coming on the scene and home theaters going into the rich folk's homes. They would look at my hearing aids and appear puzzled. Some would just come out and say, "How can you do your job if you can't hear?" I told them that as long as their ears were happy, then I would take their money. If not, tell me what isn't right and I will make it so. After all, it is THEIR ears that are important, right?
Started playing stringed instruments in 1967- first autoharp, then banjo, then piano and guitar and was in the school band playing drums from 4th grade through high school graduation (Concert Band, Marching Band, Orchestra (tympani), etc. Made the guitar my main thing when I was grounded for a Summer my Sophomore year in High School- nothing better to do.
Lost my hearing gradually. didn't wear hearing aids until I was 18. They stopped being useful when I turned 40. Went to college, got a couple of degrees in Deaf education, and now am a registered Drug and Addictions Intern. Worked with only deaf people for a while, got bored of that (try to explain music to a deaf person- you might as well talk about colors to a blind one).
Implanted with cochlear device in 2002- now I have my brain wired so I can plug stuff right into it. Yes, even a guitar. I can hear a fly's fart in a quiet room. I just got the latest model, and it is WAY too sensitive. I don't want to hear ALL that. Volume does not go to zero as programmed. I am getting that fixed in a week or so. Can't complain, when I want quiet I just turn it off.
So Hi Ya'll! Lets let the fun begin! Don't be shy now, jump on in!

Super,
You can cut and paste this intro into the proper section, or guide me to it and I will do it.

[Tarin]

Hello mark, mexican buddy here.
Just read your bio and can't manage to clos my jaw... that must be the shortest/best explained/interesting and surprising bio i've read in a long time (people at Myspace could learn how to get a message thru).