Rocket w/ Reverb

Express, Liverpool, Rocket, Dirty Little Monster, etc.

Moderators: pompeiisneaks, Colossal

Post Reply
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Rocket w/ Reverb

Post by martin manning »

amplifiednation wrote:
martin manning wrote:
amplifiednation wrote:V3a and b are tied together and at 270
Do you mean pins 6 and 1 are tied together? That shouldn't be.
Yes that is what I have. It appears that way on the layout so I thought it was correct. The grids and cathode are tied too. I thought that was the recovery tube for the reverb. I could be way off
I realized that you changed the tube numbers from the schematic... It's be easier if you called the driver V8, so all of the others would be as drawn. The recover stage is the previously unused V2b, is it not?
User avatar
RJ Guitars
Posts: 2663
Joined: Tue Nov 14, 2006 3:49 am
Location: Los Alamos, New Mexico
Contact:

Re: Rocket w/ Reverb

Post by RJ Guitars »

My meter has lead me down the wrong path on a couple occasions before I figured out the battery was dying...
Good, Fast, or Cheap -- Pick two...

http://www.rjguitars.net
http://www.rjaudioresearch.com/
http://diyguitaramps.prophpbb.com/
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Rocket w/ Reverb

Post by M Fowler »

Make sure the B5 is connected to the 100k off pin 1 V2 and 220k off pin 6 on V1.

B4 goes to 100k tied to pin 1 V1/pin 7 V2 and onto pin 6 V2

B3 goes to the pair of 100k/100k in phase inverter section.

Make sure the pair of 220k/220k in phase inverter go to ground.
amplifiednation
Posts: 2091
Joined: Sun Dec 26, 2010 6:19 pm
Location: Boston
Contact:

Re: Rocket w/ Reverb

Post by amplifiednation »

I realized that you changed the tube numbers from the schematic... It's be easier if you called the driver V8, so all of the others would be as drawn. The recover stage is the previously unused V2b, is it not?[/quote]

whoops, sorry about that.
Amplified Nation
www.amplifiednation.com
@ampnation
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Rocket w/ Reverb

Post by martin manning »

V2a's plate (pin 1) should be the same voltage as B+4, and it's not... something is wrong there. Also, V1a's plate (pin 1) is near ground at 3V, same area, so look there for a wiring error. The big current draw is from B+4, not B+3 (PI), again pointing to a wiring error around V1a/V2a.
Last edited by martin manning on Sat Feb 26, 2011 4:44 pm, edited 1 time in total.
User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

readings

Post by angelodp »

I also tested the 9k1 resistors that I removed. They had 14.77 ohms. I'm not sure how else I can test them...or if that is even correct, but it's consistent across all of the resistors.

I'm still getting a huge voltage drop from B2 to B3.

Are you saying that your 9k1 resistors are reading 14.7 ohms ?? Thats a problem if so.
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Rocket w/ Reverb

Post by M Fowler »

Just a suggestion if you want to fill in the blanks voltages on the attached voltage chart so we can identify the problem areas.

I don't know about the rest of the guys but I am lost on the voltages your getting?
You do not have the required permissions to view the files attached to this post.
Last edited by M Fowler on Sat Feb 26, 2011 10:22 pm, edited 1 time in total.
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Rocket w/ Reverb

Post by martin manning »

I agree, Mark, but the "V" numbers have to match the schematic or we'll still be confused. I guess the new reverb driver tube should be called V9 instead of V8 like I suggested above; that's already taken by the rectifier. I'm pretty sure the problem is a wiring error around V1a and V2a per my edited post above.
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Rocket w/ Reverb

Post by M Fowler »

Taylor here is my voltage chart
You do not have the required permissions to view the files attached to this post.
amplifiednation
Posts: 2091
Joined: Sun Dec 26, 2010 6:19 pm
Location: Boston
Contact:

Re: Rocket w/ Reverb

Post by amplifiednation »

martin manning wrote:
amplifiednation wrote:
martin manning wrote: Do you mean pins 6 and 1 are tied together? That shouldn't be.
Yes that is what I have. It appears that way on the layout so I thought it was correct. The grids and cathode are tied too. I thought that was the recovery tube for the reverb. I could be way off
I realized that you changed the tube numbers from the schematic... It's be easier if you called the driver V8, so all of the others would be as drawn. The recover stage is the previously unused V2b, is it not?
Fixed my post. Sorry for the confusion.
Amplified Nation
www.amplifiednation.com
@ampnation
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Rocket w/ Reverb

Post by martin manning »

I'm still looking at V2a's plate being 55V when it's supposed to be connected directly to B+4, which is 83V.
XgamerGt03
Posts: 112
Joined: Fri Feb 13, 2009 6:03 pm

Re: Rocket w/ Reverb

Post by XgamerGt03 »

martin manning wrote:I'm still looking at V2a's plate being 55V when it's supposed to be connected directly to B+4, which is 83V.
I wonder if V2b is being used as the cathode follower. Its plate is at 82V in this case. I can't see the pictures while I'm here at work but you may want to check to see if that is the case. I don't see what would cause it to be 55V unless he has a resistor soldered to the wrong place.
amplifiednation
Posts: 2091
Joined: Sun Dec 26, 2010 6:19 pm
Location: Boston
Contact:

Re: Rocket w/ Reverb

Post by amplifiednation »

XgamerGt03 wrote:
martin manning wrote:I'm still looking at V2a's plate being 55V when it's supposed to be connected directly to B+4, which is 83V.
I wonder if V2b is being used as the cathode follower. Its plate is at 82V in this case. I can't see the pictures while I'm here at work but you may want to check to see if that is the case. I don't see what would cause it to be 55V unless he has a resistor soldered to the wrong place.
I got dragged away from the build for the night. I feel like I want as accurate as I need to be on the voltage measurements. Mark sent me a chart that I will fill out tommorrow.

Thank you all so much for your help. This community is amazing and full of some great knowledge. I can't wait to get this figured out so I can start adding value to the forum
Amplified Nation
www.amplifiednation.com
@ampnation
XgamerGt03
Posts: 112
Joined: Fri Feb 13, 2009 6:03 pm

Re: Rocket w/ Reverb

Post by XgamerGt03 »

It looks to me like you are in fact using v2b for the cathode follower. Have you checked your reverb transformer? Also, if you remove that specific tube and leave all of the others in what happens to the voltage?

I see you said that you stepped away so those are some ideas for when you work on the amp next.
User avatar
martin manning
Posts: 14308
Joined: Sun Jul 06, 2008 12:43 am
Location: 39°06' N 84°30' W

Re: Rocket w/ Reverb

Post by martin manning »

XgamerGt03 wrote:
martin manning wrote:I'm still looking at V2a's plate being 55V when it's supposed to be connected directly to B+4, which is 83V.
I wonder if V2b is being used as the cathode follower. Its plate is at 82V in this case. I can't see the pictures while I'm here at work but you may want to check to see if that is the case. I don't see what would cause it to be 55V unless he has a resistor soldered to the wrong place.
Yes, that looks like the case, and V2a and b appear to be wired correctly, but, the cathode resistor on V2b doesn't look like 56k.
Post Reply