Crate schematic

[Alroc_18]

You might should read teemuk's book.
http://www.ssguitar.com/index.php?topic=711
He discusses some of the issues with "Hi-Fi" speakers for instrument amplifies.


In short, you need to find a good instrument speaker.

The cheap speaker you had my have damaged the circuit too.

Tnx :tu: I'm downloading it... and yes probably the circuit is damaged, now I'm looking for build a 100w amp that I find here http://sound.westhost.com/project27.htm as a project and meanwhile get another practice/rehearsal amp, if you guys can give me a hand on that I'll be more than happy... sorry to post it here I'll open a thread on my advances as soon as I start the project.

Greetings.

[J M Fahey]

Hi Alroc.
The "low" sound level you get is due to typical Hi Fi speakers' *very* low sensitivity. I guess nothing is broken in your amp, the "brr brr" sound when going over 6 is just normal SS harsh clipping, which wouldn´t hurt through a true Guitar speaker, which both has very high sensitivity and the "right" frequency response. Try to get a Jensen or Eminence or equivalent guitar speaker for your next project.

[Alroc_18]

Hi anyone... I'm a few hours of my sunday rehearsal, and the Crate is acting funny again...  :duh

The brrr brrr is, maybe, not normal harsh, sounds like the cone is about to give us the last exhale... jajajaja, the old speaker who is doing that is an SCM Electronics 86-105-04 4 ohm, I leave you guys a recording of the noise, http://alrocmedia.net/GX15-brokenSpk2.mp3 in the first part you can hear the original speaker doing that funny noise, the clean and overdrive channels sound good enough... in the last part you can hear the new cheap-o-speaker from unknow father Jiabailum 8ohm 100w sounds really bad on high levels... oversaturated... it is the circuit or the speakers? I need that schematics to find and maybe upgrade the GX-15 to a GX-15R and use this amp for home practicing and rehearsal vocals.

Thanks for the advices and the great book from TeemuK, wich btw is now my personal hero 

[STDog]

The noise with the SCM speaker sounds like some sort of oscillation.
Does changing the different volume controls affect it?

Are you moving the mic closer to the speaker to pickup the noise of something else?
Can you leave the mic in the position where the noise is picked up while changing the volume setting and switching channels.
Also, try the same with the HiFi speaker.
I suspect the HiFi speaker just isn't sensitive enough to pick it up.

Don't pick/strum the strings, or just use a single string, so the out of tune strings don't add beats to the audio.


If the distortion channel really doesn't have the noise, I suspect it's coming from an early stage, and a high/band pass filter in the distortion channel is blocking it. I don't know for sure how that Crate distortion circuit is done though.
(I have a GFX amp which I think is basically the same. The main tone controls are after the clean/distorted channels reconverge)

[J M Fahey]

Hi Alroc.From what I hear, there's nothing wrong with your speaker, except, maybe, low sensitivity which can't be judged in a recording. You have perfect clean sound, which masks no problem *if* they exist, so they don't. Then you switch the distortion on, which is clearly audible by the sudden and brutal increase in background noise ........ and it distorts !!
The only "unexpected" noise is something vaguely similar to motorboating, but since it lasts only six seconds and goes away on its own, it might be the beat between two close tuned strings, I don't worry much about it.  I don't think you have a problem, except, perhaps, bad shielding. 

[STDog]

Maybe I misunderstood. I thought the first 2 samples were the "old" speaker(SMC). Then he turns up the volume and/or moves the mic near the speaker so you can hear the sound.

The recording stops and he changes to the "new" speaker(generic HiFi type), with a clean and distorted examples.

[sixesdmf]

does anyone have the schematic for the crate gfx 1200h

[iceregent]

I need to fix my Crate BT220 amp, but cannot find the schematics anywhere, not even on the crate site. Any chance anyone would have one?

[Gillan Jr]

Hello poeple!!!I'm here to ask them,if someone could send me the Crate GX-15 schematic...PLEAAAAASE ...For now is only...Thank you very much!!! :tu:

[J M Fahey]

Hi Gillan Jr. , how's Ian (your father ) doing?
Does he still crack your house's windows when singing Happy Birthdays?
Now on to your amp.
I don't have it, but if you have a burnt out power chip, it's probably a very generic TDA2030 or similar, and amp makers usually follow the datasheet application faithfully.
Check the chip code, google its datasheet, compare the application schematic with your actual board, I think you'll have 95% of the problem covered.
And if you have other problems, they are usually *mechanical* ones: dirty pots, bent/rusty jacks, etc.

[FASTER]

Helloo, Ive recently bought a Crate gfx50TT and in need of a schematic of it if its available, I have power, but no sound, I tested the speaker which works, not sure if its all hooked up right. The person before me clearly took it apart so I wanna make sure its all back together right. Thank you