Search found 352 matches

by ach91
Mon Oct 29, 2012 1:36 pm
Forum: JVM Discussion
Topic: Less is more?
Replies: 14
Views: 2679

Re: Less is more?

Having the gain knob backed off is crunchier and tighter generally in every amp that has a bright cap over the gain pot. The more you back it off the more that cap is in the circuit. The more your crank the knob the less its in the circuit and the darker and muddier the tone gets. The amount of dist...
by ach91
Sun Oct 28, 2012 11:19 pm
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

If you are planning on going through all of this trouble to build an extra gain stage why not just put it right after V1A like the JVM does. Since you are going to go through the trouble of mounting it in the chassis why put it in front pf the input?
by ach91
Sun Oct 14, 2012 6:11 am
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

Well if you did the JCM 800 mods then its basically like the bright channel on a Plexi now then with just V1A (2K7 cathode) and V2A (820R cathode) being used. Just turn up the volume really or put in a MV like Charlotte did so you can crank the preamp volume on it.
by ach91
Tue Oct 09, 2012 4:49 am
Forum: JVM Discussion
Topic: Is there something wrong with me ? I like the JVM as-is ...
Replies: 52
Views: 7745

Re: Is there something wrong with me ? I like the JVM as-is

I would've kept my JVM stock if there weren't so many options possible as far as mods go with the JVM. Once I REALLY wanted to change my amp to 6550s and realized to bias them right I had to change out the bias resistors I did it and I opened up a can of worms in the process. Prior to modding my JVM...
by ach91
Tue Oct 09, 2012 1:47 am
Forum: JVM Discussion
Topic: SS tube replacements in a JVM?
Replies: 25
Views: 3757

Re: SS tube replacements in a JVM?

The only tube position that wouldnt alter tone is V4. V3 is just as important as V1,2 and 5 because V3A is the cathode follower and basically is what drives your signal into the tone stack. Changing this to a solid state tube would alter your tone. V4 really is just there for the effects loop and re...
by ach91
Fri Sep 28, 2012 4:00 am
Forum: Other Amps
Topic: Mods: Adding crunch and warmth to amp, How ??
Replies: 1
Views: 1359

Re: Mods: Adding crunch and warmth to amp, How ??

I can't zoom in the schematic to make it readable. The zoom function just brings me to a web page that makes it the same exact size and if I download it it's a .gif image which links me to use internet explorer which brings me to a web page that doesn't let me zoom either. I'd give it a shot if I co...
by ach91
Fri Sep 28, 2012 3:50 am
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

On the Haze 40 schematic R41 is the 22K resistor directly before the grid on V1B with R88 being the 470K resistor with the NF C48 cap in parallel over it before the gain pot.

Have you ever heard of people putting bypasses like this on amps Casey?
by ach91
Thu Sep 27, 2012 8:59 pm
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

Charlotte wrote:also I would like to keep the .47 uF on the R41,I like the sound and gain of it ,but can it do any harm?
I'm not really sure to be honest. I've never seen that type of setup before. I would ask Casey_Butt. If it were me I'd just take it off for good measure.
by ach91
Thu Sep 27, 2012 8:55 pm
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

Yes, C36 & C41 on the Haze 40 and C25 & C32 on the Haze 15. You can go ahead and try it if you want to. The reason I didn't really mention it is because some people were saying the JCM 800 mods made their Haze sound thinner which is exactly what will happen. So with this mod taking out some bass I j...
by ach91
Tue Sep 25, 2012 5:08 am
Forum: Other Amps
Topic: AFD100 schematic
Replies: 14
Views: 11411

Re: AFD100 schematic

Yeah that makes sense. I only really glanced at it. It makes sense to just wire that triode in since it's just sitting there. Might as well put it in the circuit rather than sit there not being used. As for the 820R last stage it probably doesn't make a world of difference anyways. I have the last s...
by ach91
Tue Sep 25, 2012 4:55 am
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

Uhh.. On the Haze 40 R41 is the resistor that goes into the grid of V2B, R22 is the plate resistor for V2B, and R19 I can't even find on the Haze 40 schematic.. Are you talking about the Haze 40 or 15? I assume 40 since that's what we've discussed before and is the amp you have in your signature.. I...
by ach91
Wed Sep 19, 2012 12:21 am
Forum: JVM Tubes - Choice and Preferences
Topic: Basic tube question
Replies: 7
Views: 1827

Re: Basic tube question

Well V3 is has one triode as the cathode follower.. Using a cheap quality tube here could lead to tube failure. However, JJ's while being cheap cost-wise make pretty rugged preamp tubes and wopuld be fine here. Yes V4 doesn't really shape tone. As far as replacing tubes.. V1-V4 will probably last wa...
by ach91
Sun Sep 16, 2012 6:59 pm
Forum: Other Amps
Topic: Convert Haze 40 into JCM 800
Replies: 232
Views: 64936

Re: Convert Haze 40 into JCM 800

Which is exactly why I have my Haze 40 too. Glad to hear its working out. If you want some more gain you could try a .68uF or 1uF over R41 too. Jackie, lol sorry to burst your bubble dude but yeah they don't have Haze 40 Heads. There's the Haze 15 head but cranked with those 6V6s it might sound pret...
by ach91
Fri Sep 14, 2012 9:45 pm
Forum: Other Amps
Topic: "New" DSL?
Replies: 57
Views: 8686

Re: "New" DSL?

Well yea no one likes hearing about jobs getting lost that goes without saying. But as far as as production quality goes just because it's made somewhere else then where the company is based doesn't mean that the product automatically is a piece of crap. I don't like companies outsourcing production...
by ach91
Fri Sep 14, 2012 12:44 pm
Forum: JVM Tubes - Choice and Preferences
Topic: New svetlana el34 for Marshall jvm, question?
Replies: 11
Views: 3725

Re: New svetlana el34 for Marshall jvm, question?

For the time being you could just take two of the EL34s and run them in either the inner or outer two sockets. I don't think you HAVE TO do impedance matching on the JVM but if so an example would be to connect your 16 Ohm cap to the 8 Ohm jack or an 8 Ohm cab to the 4 Ohm jack. Don't forget to bias...