Dialing in your plate voltage and tubes (NON HRM)

[tonejunkie]

Cool guys. I will have to get that 124 schematic. When I get the resistors I will comment on what I think of the voltage changes. I figured out why my cap is larger, it is really a .0047 not a .005. I will change that. More to come.

[tonejunkie]

Here are some pics of my rig. I use this for funk, reggae, and blues gigs I have. My main band is The Groove Patrol. There are no dumble tones on the site but there will be some day. www.thegroovepatrol.com . This is what I will be working with.

Signal Chain
Guitars: 2006 335 Fat neck w/ Gibson Pickups, 2007 Chambered 57 Goldtop w/ Wolftone Dr. Vintage in neck and Marshallhead in Bridge all with A2 magnets.

Cable: Gepco XB20UB and Lava Cable solderless on the pedalboard.

Pedal Board: Teese RMC3 Wah, Soul Pressure, RC Boost, MXR Auto Q (True Bypass mod), Peterson, Octron, Hilton Volume Pedal (it will be a Hilton next week), Vibe, DL4

Amp: High Plate Skyliner Non HRM

Rack: Dumbleator, Suhr MiniMix 2, TC G Major.

Cabinet: Pine 2x12 with Celestion G1265's

[David Root]

Tony, that's interesting about taking V1 plates down to 175-180V, that is between late tweed and early brown Fender territory. I tried that in my dumbleized 5F6A/6SL7/8417 and it sounded good.

I'll try it in my '70s combo build I think.

[dogears]

RF is more in the 200V range. As a reference of course....

[talbany]

Tony, that's interesting about taking V1 plates down to 175-180V, that is between late tweed and early brown Fender territory. I tried that in my dumbleized 5F6A/6SL7/8417 and it sounded good.

I'll try it in my '70s combo build I think.

Dave
Yeah!! my theory is the reason why it worked so well in the 70's is those amps are more open running.. Less losses in that stack (or at least the one I did)..not as much NFB and the funky OD so it worked..I would like to hear your D-ized 5f6 I always wanted to do a D-style with the octals..I'll bet it HONK's My 49 Tweed TV Pro w/6SLs is thick...With a Les Paul can get that Billy Gibbons Brown sugar/ Shakin your Tree tone .. I love that 1st album..

Scott
Thanks for the RF tip..

Tony

[Structo]

Cool guys. I will have to get that 124 schematic. When I get the resistors I will comment on what I think of the voltage changes. I figured out why my cap is larger, it is really a .0047 not a .005. I will change that. More to come.

That difference between .0047 and .005uF is not enough to worry about IMHO.

Everybody stresses how important the tube voltages are and I agree.
You can really change the tone and feel of the amp with the voltages.

[tonejunkie]

I got my mouser order I may still need to order a couple of values to raise the voltages a little (I thought I purchased enough range of resistors to get up to 290 on the PI). The string is 1.5k, 22k, 2.2k, and the fet simulator 150k .

The voltages are:
CL 186 190
OD 198 200
PI 280 286

I am headed out to a gig I will post my tone impressions tomorrow.

PS. My string from the first post was 2k, 20k, 2.2k. (for comparison).

[Structo]

Voltages look good to me.

[tonejunkie]

Last night playing with a 4 peice jazz, funk, improv thing the amp felt pretty good. I noticed more clarity and it cut though a little easier that it had before when I was running it around 185 on the 1st preamp tube and 270 on the PI. You know that feedback thing that these amps do even on the clean channel when you hold a note, it seems to do that less now. Wonder why. Just before I put the amp back in its head box I tried the dropping string:

1k, 22k, 2.2k and the fet resistor and got:
CL 190 194
OD 200 204
PI 284 289

I would like some of that singy feedback thing to come back is that due to voltage changes?

Before I start tweaking the overdrive but I would like to get my clean channel to get a little more lively first. Maybee I'll try raising the bright cap on the master from the 15p I have in there now. Any other ideas?

Here is some clips with a zoom H2 in a crappy room. I think its pretty accurate to what I am hearing accept a little distortion on the top from the zoom. Both clips are using a Dumbleator, Suhr MiniMix and a small amount of reverb. I don't do much recording of myself but these clips lead me to believe I need to do more (clam).

[talbany]

Before I start tweaking the overdrive but I would like to get my clean channel to get a little more lively first. Maybee I'll try raising the bright cap on the master from the 15p I have in there now. Any other ideas?

Before you go changing things go through a few tubes first.. New ones!! including PI..


Tony

[Structo]

Those voltages appear to be almost perfect though some like higher on the PI.
But if the tubes you have in now sound good I think I would only experiment with the PI tube.

Have you adjusted the PI trimmer?

I had trouble when I first did it because I didn't understand how it was working.

Due to the capacitive load there it takes a second or two for the adjustment to be heard.

So make the change in small increments.

Turn up the amp quite loud and lightly brush the strings with your thumb.
Single coils seem to work best for this with the neck pickup selected.

When you find a spot where the notes seem to bloom into harmonic feedback that is your sweet spot on the PI balance.

Others also have said that correlates to around 5-6v higher on the input side plate of the PI.
Hope this helps.

[tonejunkie]

I swapped some tubes and have played the amp out a couple of times. I think I am starting to feel comfortable tweaking the tone with tubes and voltage. I settled on a sovtek LPS in the PI. This tube did drop my PI voltage to around 185 on the input side but it had great harmonics and brought back the singy quality. I also settled on JJ EC83 in the OD as as well CL I. The changes above in the thread as well as these have helped tighten up the amp as well as keep that singin thing happening. I am going to order more tubes to try and find a couple of other keepers sets and then start another thread to see if we can tweak my overdrive a little. Thanks for all of your help.

TJ