My first Rocket... Need help!

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

Moderators: pompeiisneaks, Colossal

User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

Nice amp

Post by angelodp »

Yes indeed, looking good. Soon... soon man. Get ready for TONE.

Ange
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

"redo" finished!

Post by showsii »

Hello everyone,

I have finished re building my Rocket. I hope that this looks cleaner to everyone and is a step in the right direction as far as lead dress goes.

I have a few voltages right now and will get the rest very soon.

B+1-286.4
B+2-278.5
B+3-207.9
B+4- 181.1
B+5- 178

There still is NO head room in this amp guys! I don't know what I am doing wrong. It is still very dirty at 10:00. Once again ZERO head room.

I replaced all the tubes... same thing.

Let me get some more voltages and maybe we can further discuss what might be wrong. Until then here are some pictures for any obvious mistakes on my part.
You do not have the required permissions to view the files attached to this post.
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

woops

Post by showsii »

I accidentally started a new topic with more pictures

Could some one tell me how to link it back over here??

Thanks

Ian
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Voltage chart

Post by showsii »

Here we go
You do not have the required permissions to view the files attached to this post.
Last edited by showsii on Thu Mar 17, 2011 4:29 am, edited 1 time in total.
User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

Voltage chart

Post by angelodp »

Your voltage readings look good, within tolerance I believe. Is your speaker in good shape and operating nicely on another amp? You are matching impedance. You swapped guitars and cables.

Ange
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Re: Voltage chart

Post by showsii »

angelodp wrote:Your voltage readings look good, within tolerance I believe. Is your speaker in good shape and operating nicely on another amp? You are matching impedance. You swapped guitars and cables.

Ange

Speaker- yes

Impedance- yes

Guitars and cables- yes

Hmmmm what could it be?

Ian
User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

what

Post by angelodp »

What guitar and speaker? Humbuckers are kinda growly.

Ange
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Re: what

Post by showsii »

angelodp wrote:What guitar and speaker? Humbuckers are kinda growly.

Ange

American dlx Tele- single coils/ Japanese Tele single coils

Vintage 30/ weber blue dog 50 watt both 1x12 cabs


Ian
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Re: My first Rocket... Need help!

Post by showsii »

https://tubeamparchive.com/viewtopic.php?t=14188 more pictures


Would changing r7 from 56k to 68k help my cause any? or should this not matter in my situation?


Ian
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

sound clip

Post by showsii »

Here is a clip

Volume- 10
Treble and bass- 12
Cut- 2
You do not have the required permissions to view the files attached to this post.
User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

Dirty

Post by angelodp »

Ok so we need some troubleshooting guys.
sunnydaze
Posts: 174
Joined: Tue Sep 09, 2008 9:15 am

Re: My first Rocket... Need help!

Post by sunnydaze »

The spreadsheet with the expected voltages has the grids on the power tubes grayed out. Not sure if you actually measured the voltages on the power tube grids or just skipped it because those pins are grayed out on the sheet. If you haven't checked, you may want to see if you can measure any DC voltage - if so, caps might be leaking DC.

I had this problem on my Rocket which was built from a Ceriatone kit with the half power switch on the cathodes of the power tubes. I found that using the switch with while in play mode caused one of the caps to leak DC. Took me awhile to figure that out because all my voltages (except on the grids were very close to as expected. I ended up taking out the half power switch as I didnt' really like the half power mode anyway.

DC on the power tube grids killed the headroom and generally made the amp sound bad. After correcting, the amp had a great clean sound and a good bit of headoom.

Hope this helps.
Mike
User avatar
angelodp
Posts: 2157
Joined: Tue Jan 15, 2008 2:45 am
Location: L.A.

good info

Post by angelodp »

Mike, good info, I am gonna run in and check my half power switch. I gotta say I do not use it much anyway.

Ian you don't have a half power switch but you can check those voltages and see if you have leaky caps.

A
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Re: My first Rocket... Need help!

Post by showsii »

sunnydaze wrote:The spreadsheet with the expected voltages has the grids on the power tubes grayed out. Not sure if you actually measured the voltages on the power tube grids or just skipped it because those pins are grayed out on the sheet. If you haven't checked, you may want to see if you can measure any DC voltage - if so, caps might be leaking DC.

I had this problem on my Rocket which was built from a Ceriatone kit with the half power switch on the cathodes of the power tubes. I found that using the switch with while in play mode caused one of the caps to leak DC. Took me awhile to figure that out because all my voltages (except on the grids were very close to as expected. I ended up taking out the half power switch as I didnt' really like the half power mode anyway.

DC on the power tube grids killed the headroom and generally made the amp sound bad. After correcting, the amp had a great clean sound and a good bit of headoom.

Hope this helps.
Mike

Mike,

Thanks for the help! I will measure the grids on the power tubes. I didn't at first because they were grayed out, (newbie mistake).


I am suppose to have 0v DC on the grids correct?

Thanks

Ian
showsii
Posts: 87
Joined: Wed Feb 09, 2011 9:12 pm

Re: good info

Post by showsii »

angelodp wrote:Mike, good info, I am gonna run in and check my half power switch. I gotta say I do not use it much anyway.

Ian you don't have a half power switch but you can check those voltages and see if you have leaky caps.

A
Ok I measure the Grids of V4,5,6,7

I get .18mv on 4,5

And .8mv on 6, 7


Does this mean I have leaky caps, or is this amount immaterial?


Ian
Post Reply