Clean tone on low gain Channel

[mikebuzz]

I am having a tough time getting a CLEAN tone on my 36w Tmb , a little about the amp , IT HAS
1. VR mod ( variable reg) Very nice
2. Master gain control (PI type ) so so ?
3. channel switching ( relay based ) this rocks IMO

All sections/mods work fine !!

on the clean ch. low input volume, masters all the way up it is still is DIRTY !!

Any ideas to clean it up ??

PS: I run 16ohm 2x12 Webers ( 1 blue dog . 1 silver bell )

LAter
Buzz

[krx]

on the clean ch. low input volume, masters all the way up it is still is DIRTY !!

Any ideas to clean it up ??

I'd start by turning down the master to about halfway... Actually, I'm not sure why you'd want both a master volume and VVR. I'd just ditch the master myself.

Do you have a schematic? How does the amp sound generally? What kind of dirty are we talking about? What kind of pickups are you pushing it with? We need more info to figure out if you've done something wrong in the design or construction or if you just need to back off a little to get a clean tone.

[mikebuzz]

I use mainly a strat , I dont use the master that much it's a leftover mod !
I have tried all settings for the most part it just never gets CLEAN ! ,

It also depends on how hard I play of course , I have set the input voulume to 2 or so and it helps some , Maybe a gain change on the clean CH > ?
( increase the cathode res. value or decrease ?? I forgot )

Thanks
Buzz

See the attachement

[krx]

Does the amp sound good when its dirty or does it sound like something might be off? Were you not getting any cleans before you installed the VVR?

With a 36W and a strat you should definitely have more cleans than it sounds like you're getting (try rolling back the volume knob on your guitar about 1/3). I'd start by checking the plate, cathode, and screen (where present) voltages of all your tubes to make sure something isn't biased funny. Also, do you have a schematic for your signal path? It's also possible you've just built a higher gain amp than you thought you did .

[mikebuzz]

It's always been fairly DIRTY sounding even as an 18 watter ( did the conversion to 4 el84's )

I did not notice a real difference after all the mods ( could have been some changes but nothing real bad ?? )

I will try to get some voltage measurements ( I have a broken ankle right now so it might be hard ? )

I have heard some mp3's from other 18 w's and they were much better sounding

Hopefully I can get this sorted out we are recording 4 tracks now and I need this thing working

BTW it's a Richie TMB build

[krx]

Sounds like your VVR is okay then. The Richie TMB isn't the cleanest but you should have more headroom than it sounds like you do. Definitely check out those voltages, and maybe someone else can chime in with some other ideas in the meantime.

Other easy things to check: tubes, speakers. Try different ones if you have them.

[mikebuzz]

I'm starting to think tubes ? I will check the voltages ver ysoon to make sure they are OK

WHere do you get your tubes ?

Buzz

[zaphod_phil]

I'd start by turning down the master to about halfway...

+1

These amps are great for power amp distortion. Setting the MV too high will overdrive the power amp. You should be able to get enough volume from a 36W with the MV turned part way down.