High-Gain JCM800/2204 Build

[FourT6and2]

Came out great. How does it sound in the room?

Sounds fantastic. I'm having a hard time recording it though. I've tried my phone, my laptop, and a DSLR. None of them really pick up how it sounds in the room. But I'm uploading a video as we speak. Listening on my laptop speakers, sounds like crap. But listening through my Bose QC25 headphones and it sounds great. So I have no clue how it will sound to anybody else haha.

Here you go.

Mayones Duvell Elite MBC with Seymour Duncan Nazgul
Bogner 4x12 with G12M-25 Greenbacks (batting/insulation removed)

Link: https://www.youtube.com/watch?v=zksgyAYSu-A&t=1s

Sounds tight and modern. I like it.

Will probably loosen up a little more with a few more hours on it.

I don't want it any looser haha.

 

[FourT6and2]

12' away is fine, but closer would reduce room coloration. Closer than ~6' might overload the camera mic. I figure a maximum ~130dB peak at ~2.4kHz from ~6' pointed directly at one of the G12M-25 (that's without any efficiency loss). Modern MEMS mics in cell phones can handle 130dB or so, so it should be OK depending on the cell phone. Otherwise, 12' is fine.

Consider that it's not uncommon to mic a Greenback dead center with an SM57, and the SM57 has a 6dB lift at 3-6kHz. MEMS mics are entirely flat and uncolored from 20Hz~20kHz. It might sound great right on-axis.

I actually recorded that clip with three different devices at the same time. My iPhone and laptop webcam both made it sound horrible, like all grainy and raspy... The video I posted is with my Nikon D800 DSLR.

The recording is a little bassy/resonant, but I can get the gist of it. Sounds good, has a much better growl, and grit than the chupacabra's have IMO

I can try to mess with the RAW video file a bit to reduce some resonance. How's this sound in comparison?

Link: https://www.youtube.com/watch?v=b97iXVaKliE

 

[scottosan]

Where are the diodes?

 

[FourT6and2]

Where are the diodes?

In the video you can see the two wires coming out of the chassis? I just have them on the rotary switch below the amp stand for now. Will hard wire them soon.

 

[scottosan]

Where are the diodes?

In the video you can see the two wires coming out of the chassis? I just have them on the rotary switch below the amp stand for now. Will hard wire them soon.

ahhh. I thought I was loosing my mind

 

[FourT6and2]

Where are the diodes?

In the video you can see the two wires coming out of the chassis? I just have them on the rotary switch below the amp stand for now. Will hard wire them soon.

ahhh. I thought I was loosing my mind

I thought about saying the diodes were in my parts box and fucking with you. Would be funny to see you try to figure out how I got all the clipping without them lol.

 

[FourT6and2]

...

 

[Deanmachine]

Sounds killer you are very talented !

 

[GCKelloch]

12' away is fine, but closer would reduce room coloration. Closer than ~6' might overload the camera mic. I figure a maximum ~130dB peak at ~2.4kHz from ~6' pointed directly at one of the G12M-25 (that's without any efficiency loss). Modern MEMS mics in cell phones can handle 130dB or so, so it should be OK depending on the cell phone. Otherwise, 12' is fine.

Consider that it's not uncommon to mic a Greenback dead center with an SM57, and the SM57 has a 6dB lift at 3-6kHz. MEMS mics are entirely flat and uncolored from 20Hz~20kHz. It might sound great right on-axis.

I actually recorded that clip with three different devices at the same time. My iPhone and laptop webcam both made it sound horrible, like all grainy and raspy... The video I posted is with my Nikon D800 DSLR.

The recording is a little bassy/resonant, but I can get the gist of it. Sounds good, has a much better growl, and grit than the chupacabra's have IMO

I can try to mess with the RAW video file a bit to reduce some resonance. How's this sound in comparison?

Link: https://www.youtube.com/watch?v=b97iXVaKliE

Much less bass for sure. Did you use a resonance/reverb reducing EQ or just reduce the bass?

The DSLR mic sounds great from what I can hear, but the angle of the rear top to front right corners of the cab indicates it's ~40d off-axis. I'd still like to hear it on-axis (and closer up) when you get a chance. No need to eq it afterwards.

I've read that the original JCM's shipped with G12-65 speakers. The G12M-25 are very nice, but not that tight in the bass.
What do you think about the G12-65?

 

[FourT6and2]

12' away is fine, but closer would reduce room coloration. Closer than ~6' might overload the camera mic. I figure a maximum ~130dB peak at ~2.4kHz from ~6' pointed directly at one of the G12M-25 (that's without any efficiency loss). Modern MEMS mics in cell phones can handle 130dB or so, so it should be OK depending on the cell phone. Otherwise, 12' is fine.

Consider that it's not uncommon to mic a Greenback dead center with an SM57, and the SM57 has a 6dB lift at 3-6kHz. MEMS mics are entirely flat and uncolored from 20Hz~20kHz. It might sound great right on-axis.

I actually recorded that clip with three different devices at the same time. My iPhone and laptop webcam both made it sound horrible, like all grainy and raspy... The video I posted is with my Nikon D800 DSLR.

The recording is a little bassy/resonant, but I can get the gist of it. Sounds good, has a much better growl, and grit than the chupacabra's have IMO

I can try to mess with the RAW video file a bit to reduce some resonance. How's this sound in comparison?

Link: https://www.youtube.com/watch?v=b97iXVaKliE

Much less bass for sure. Did you use a resonance/reverb reducing EQ or just reduce the bass?

The DSLR mic sounds great from what I can hear, but the angle of the rear top to front right corners of the cab indicates it's ~40d off-axis. I'd still like to hear it on-axis (and closer up) when you get a chance. No need to eq it afterwards.

I've read that the original JCM's shipped with G12-65 speakers. The G12M-25 are very nice, but not that tight in the bass.
What do you think about the G12-65?

I used to have G12-65s. They are a good speaker if you have a bright amp. But you need to crank the amp incredibly loud to get the speakers to give up the goods. Ultimately, I prefer the raunchy growl of Greenbacks. I have two other cabs I have yet to try with this amp though. One is a Mesa 2x12 with V30s and the other is another Bogner 4x12 with G12H-65 Creambacks with the insulation/batting still in the cab.

Will get another clip just for you in another day or so. I'll put the camera on-axis and closer.

 

[GCKelloch]

Those other cabs should be nice to compare. You mean G12H-75?

 

[technomancer]

Turned out great!

 

[FourT6and2]

Those other cabs should be nice to compare. You mean G12H-75?

Yes, 75 not 65

 

[FourT6and2]

Turned out great!

Thanks buddy!

 

[GCKelloch]

Really solid playing, BTW. I especially liked the Tool stuff. V30 and G12H are brighter speakers above ~3kHz than G12M, so it will be pretty bright on-axis, but it's worth hearing the high end character of the amp. V30 are generally more "piercing" than even the G12H-75 due to the stronger "metallic" ~3kHz range. The G12M-25 should cause the least ear-fatigue.

 

[FourT6and2]

Really solid playing, BTW. I especially liked the Tool stuff. V30 and G12H are brighter speakers above ~3kHz than G12M, so it will be pretty bright on-axis, but it's worth hearing the high end character of the amp. V30 are generally more "piercing" than even the G12H-75 due to the stronger "metallic" ~3kHz range. The G12M-25 should cause the least ear-fatigue.

Yeah that's one of the reasons I like the Greenback so much.

For what it's worth, look how I have the amp EQ'd and you'll see I don't like a lot of treble/presence. I've got the treble/presence really low and the mids cranked. I don't understand how some people run their treble/presence so high sometimes. But whatever gets the job done I guess

 

[CrazyNutz]

One more clip. This time with Aldrich pickup: https://www.youtube.com/watch?v=I2nYmhO5LZM

There it is. Sounds great!

 

[GCKelloch]

Really solid playing, BTW. I especially liked the Tool stuff. V30 and G12H are brighter speakers above ~3kHz than G12M, so it will be pretty bright on-axis, but it's worth hearing the high end character of the amp. V30 are generally more "piercing" than even the G12H-75 due to the stronger "metallic" ~3kHz range. The G12M-25 should cause the least ear-fatigue.

Yeah that's one of the reasons I like the Greenback so much.

For what it's worth, look how I have the amp EQ'd and you'll see I don't like a lot of treble/presence. I've got the treble/presence really low and the mids cranked. I don't understand how some people run their treble/presence so high sometimes. But whatever gets the job done I guess

Absolutely! Most players aren't aware of how tone stacks really work. I didn't understand it until I downloaded the Duncan Amps 'TSC' app, which I strongly recommend. I just use amp sims now. I generally keep the Middle up, Treble way down, and Presence up for better high end harmonic dynamics. Neg feedback reduces distortion and creates a compression effect, but the amp then breaks up more abruptly when it does break up.

G12H-30 (55Hz) & G12M-25 is probably my fav speaker IR combo. The M softens the high end of the H a bit, and the H adds bass depth and high end detail to the M. I like an SM57 on the M and a U67 on the H -- mostly on-axis. The sound softens a bit moving a mic in from ~2" to 0", so it's not as metallic/piercing. It has to do with how the cone modes align at the mic diaphragm.

 

[FourT6and2]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

 

[scottosan]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?