Crate V5 mods... anyone?

[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

[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