2 x el84 Rocket thin and shrill!!

[surfsup]

looks to me like your bass pot is wired in reverse. Hmm looking at the layout I see pins 1 are connected btwn T and B pots. I thought bass 3 was signal to Treb 1. Maybe I am incorrect which is likely.

[angelodp]

what is the CR combo on the Volume pot wiper?

[surfsup]

Okay this is driving me nuts. I see some pics of other rockets where pins 1 are connected. This doesn't seem right to me:

Turning the shaft clockwise (CW - by convention, to move pin 2 physically closer to pin 3, and increase (for example) volume) will select a different point along the resistance element, and forms a voltage divider, so the attenuation of the signal is proportional to the rotation of the shaft. At the fully clockwise position, there is close to zero ohms in series with the signal, and the full resistance of the pot to earth. Attenuation at this setting is zero (assuming a zero or low impedance source - this is often overlooked!), and this is full volume (maximum signal level).

To get more bass, you turn the knob CW, which puts the wiper to pin3 (meaning more bass is passed with close to zero resistance). So with pin 1 going to treble pot's pin 1, that would mean the pot is wired in reverse, yes?

[Lonely Raven]

Hey Surf, that board material looks familiar. Wasn't someone trying to find something like that for a build?

[angelodp]

Thats the red stuff from Watts Tube Audio

[mbailey]

the RC on the vol pot are there to block the dc from the guitar added per the vvr instructions. the board material is bakelite I got from a machinist buddy of mine.

[angelodp]

Ok , but you don't have the VVR in yet right. I wonder if those RC for the VVR are required until the VVR is onboard?

A

[mbailey]

vvr is in.

[angelodp]

.047 220k eyelet looks like a possible cold solder?

[soma_hero]

It looks like your input is going shielded wire --> 68k --> .047uF --> V1a grid.

This means the grid doesn't have a ground reference. Usually the volume pot on the guitar would serve as the grid reference but since you've put that coupling cap on the grid, you have blocked a DC path to ground. If you keep this coupling cap, make sure you put a 1M from the grid to ground. Read the VVR packet to see where Dana explains this.

[angelodp]

Here is a reference to the VVR install, at least the way i did it.

http://i260.photobucket.com/albums/ii9/angelodp1/72.jpg

[mbailey]

1M to ground is mounted @ the input jack...see pics of input jacks

[azatplayer]

1M to ground is mounted @ the input jack...see pics of input jacks

Like soma hero says, the cap at the grid is blocking the ground reference the 1meg provides.

[surfsup]

1M to ground is mounted @ the input jack...see pics of input jacks

You have to move it to the pin so it is between the tube and the cap. You have it between input and cap.

[img1000]http://www.chicagocadcam.com/ChrisHahn/xen10/INPUT.jpg[/img]

[mbailey]

ok I see what you guys are talking about so i corrected the issue by connecting the 1M to grnd at the tube socket pin. but the amp still sounds bright and fizzy. not pleasant sounding at all? I've built a few amps and this is by far the worst sounding yet any ideas.