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/18W_lite/chassis_pt2/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]

Crate V5 Ressurection

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):rockon:

 

[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]

Saying howdy to da gang

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).

 

[Bloozcat]

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?

Try going over to www.sewatt.com and sign up. There's a new Crate 5 watt discussion just starting there. There's not much info yet, but it may generate some. There's not a whole lot of love there for the Crate 5 watt circuit, so be forewarned. It might need darn near a whole new circuit...

EDIT TO ADD: I see our new member deafelectro has already been in the Crate discussion on sewatt.co as his alter ego Manoteal...I thought his post here looked familiar...

 

[Tarin]

Now back to the main concern: upgrading the V5.

Deafelectro... That's some great task you've acomplished in the little amp. i might catch you up on sending the board to get modded and be the first one to review and experiment with your findings.
I already got your email so i'll get in touch with you next week to make this happen.
Now for the speaker issue... is there any way of including one of your leftover Eminence's in the picture?

 

[deafelectromark]

Myspace message failure

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).

Thanks C.
Your last line is cryptic- what do you mean concerning Myspace? That they can't speak succinctly? It is a skill after all. I do become quite long winded (see first post above), but last night you (and the rest of us) got lucky. I was passing out from lack of sleep. I just HAD to say what I said. That said- let the music begin!
M:beer:

 

[jim p]

crate v5 mods

I bought a V5 from Musicians Friend for 80 bucks and have started modifying it. I have two Epi valve Jr. Amps one that I added reverb, triode pentode switch, and Alnico Weber speaker to and the other with FET input high voltage regulator and 6V6 installed. I saw the schematics for the V5 on the web and can see right away they have an amplifier with a solid state preamp (TL072) and tube output not what most people want but easy to fix. Getting the amp found the stock speaker is probably not a guitar speaker so first thing was playing it through the valve Jr speakers also a pair of Jensen 10 special designs made a big difference. So ordered a new speaker from Ted Webber (they have 15% off right now so 43 bucks total with shipping) they make the stock speaker in the old valve Jr. I think. For circuit mods so far I did not remove the Op Amp because it is used for high frequency bypass (above 100Hz) and pre emphasis (boost the highs so the tone control can take them out or pass them through). So I removed R13 to change IC1-A to unity gain and use as a high impedance buffer to not load down the guitar pickups. Next removed C26 changed C24 to 47nF (Note this should be 100nF) removed C27 and installed a 33k resistor in its place removed the 250k pot to use as a volume control after the tone stack. Lifted the 100nf C25 at the node connecting it to R2 and R1 putting a 33k resistor with a 10 nF cap accost it in series (this is now the pre emphasis for the tone stack) With these changes if you over drive the amplifier input with overdrive instead of the OP Amp clipping (awful noise) the first stage tube will clip (as man and god intended when tube amps were created) Next on the tone control changed C6 to 25 nF removed C5 (not sure where a frequency this high is going to come from) and removed C4 (so when you turn the tone control all the way up it does not go to no highs) Now to install the volume pot removed R15 and R27 connected the 250K pot CW1 that was in the Op Amp feedback to ground on the wiper full CCW side connected the wiper to junction of R15, R27, R7 and the grid of J2-A and the third terminal of the pot to junction of R29 C28. Now the tone is set to flat at a quarter turn (9 o’clock position). Then checked the output of the amplifier with a frequency generator and scope and found that it did not clip equally at high volume and started to oscillate. Fixed that by lowering the cathode bias resistor to what the data sheets call out for 270 ohms. Also changed R22 the resistor in series with the power indicator to 150 ohms but it is still to bright will probably go to 220 ohms also it is a light bulb not an LED.
As always if you do mods to a tube amplifier be careful of the high voltages in this case a plate voltage of 316 volts. There is a bleeder resistor R24 so that helps but use a volt meter. And always remember the one hand rule do all your probing with one hand make sure no other part of your body or your other hand is tied to ground.
I changed the value of C24 above found lowest frequency from guitar to be 82Hz not 190Hz.

 

[Tarin]

Wow, that's some major modding. Unlike what Deafelectro achieved with his more simple mods.
I've been in touch with Deafelectro for him modding my V5 since he's is the only mod i've come up in the internet.
But now that you have accomplish another one...it's only fair to take in consideration, any clips? pics?

 

[jim p]

Re: Crate V5 mods

I have no pictures or sound clips right now. Would like to post a marked up schematic if I get a chance maybe pics. It sounds like a lot of mods but it’s not really but maybe that is because I am an electronic engineer in analog design. I did all the mods with no cuts to the PC board I did have to attach wires to the volume pot to connect it the pc board and add electrical tape under it to prevent a short to the board. All the other mods except the pre emphasis mod (33k ohm with 10nF in parallel between C25 and R1, R2) are removing components and leaving them out, changing there value or in the case of C27 replacing it with a resistor. At the least I would change R17 to 180 ohms to stop the oscillation in the EL84 output tube I just paralleled it with another 330 ohm 2 watt (165 ohms) as a quick modification. With the Op Amp input I just wanted to use it as a buffer circuit with minimum gain (equal to loss in pre emphasis circuit) so if you overdrive you will clip the first stage tube. I was hoping that I could fit a set of dual concentric pots in place of the two pots so I would have gain, tone, volume and reverb controls on the front panel. I am going to add reverb using a Ruby tank from a Crate V33 head that I changed to an Accutronics 3 spring tank. Will probably change the output tube to a 6V6 this is for my son as a practice amplifier he likes Fender amps with reverb. Good chance will need a triode/pentode switch also. I have modified the Crate V33 head and a Crate V50 and have a V18 (will change to 6V6 output class AB) on order like fooling with tubes and these are so cheep for what you get. You have to remember it is hard to kill a tube (as long as it is cathode biased) unlike transistors, fets and ICs. If you do something wrong will probably just get no sound out.

 

[jim p]

Re: Crate V5 mods

I have attached pictures of mods and sections of schematic where changes were made. I may do a step by step explanation of the modifications in the future.
Error value of C24 should be 100nF not 47nF found lowest frequency from guitar is 82Hz not 190Hz.

 

[Tele-Dave]

Can you please post this at a higher resolution, or maybe link as a pdf. When
trying to magnify, all it does is blur.

Thanx,--- Dave

 

[Tarin]

Crate V5 schematics

 

[Tarin]

Jim_P... thanks a lot, i'll take a look at what you've done and maybe i'll do thos mods to mine, although a step by step will help a lot.

I'm pretty sure that this thread is gonna recieve lots a visits cause i know theres a lot of people waiting for a DIY mod for this little amp.

I have some pics of what Deafelectro did to his and it's different from what you did... i would like to post them but, i'll need deafelectro's permission for that.

 

[Tele-Dave]

Crate V5 schematics

Thnx for schem.........Dave:bravo: :beer: