+1 on possibly bad or dirty pot.Trapland wrote:The treble control workers normally when full up or down.
New user, first build, almost works!
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Re: New user, first build, almost works!
I build and repair tube amps. http://amps.monkeymatic.com
Re: New user, first build, almost works!
I have disco necked the treble pot and it tests fine, at about 241k on both sides with no weirdness in the taper. I even checked for intermittent shorting to the pot case. Nada. I hoped like hell that it WAS a bad pot!xtian wrote:+1 on possibly bad or dirty pot.Trapland wrote:The treble control workers normally when full up or down.
Teleguy61: I thought I was the first ever to build a Natalie! I've scoured the net looking for anything on it but nothing until you. Did you try it with EL34s? I may. I think mine sounds fairly decent, but I always intended to run it near flat out, with the PPIMV just there to take the edge off and help slide it into the mix better.
I usually run the presence at about 6 on my favorite JMP, and its already pretty bright. I like that, sparkly, with a tight bottom mostly coming from a big old box full of G12-65s. I think I will convert to the classic Marshall presence and see what that sounds like.
Anyway, disconnecting the presence still doesn't fix the treble. Weird huh?
Re: New user, first build, almost works!
I did not try EL34s, but I did run it a bit with 2X6L6s, and that worked well.
The situations I was using it in were not loud enough to be able to open the PPIMV, and that would have helped. I think that type of MV really chokes an amp down.
If all connections are good, all parts in the tone stack circuit are correct, and your pot checks out ok, I would try subbing a different pot in. The tone stack is a passive circuit driven by a cathode follower, leading to a coupling cap.
There's not that much that can go wrong in there besides wiring errors or defective parts.
The situations I was using it in were not loud enough to be able to open the PPIMV, and that would have helped. I think that type of MV really chokes an amp down.
If all connections are good, all parts in the tone stack circuit are correct, and your pot checks out ok, I would try subbing a different pot in. The tone stack is a passive circuit driven by a cathode follower, leading to a coupling cap.
There's not that much that can go wrong in there besides wiring errors or defective parts.
Re: New user, first build, almost works!
Maybe.Trapland wrote:Anyway, disconnecting the presence still doesn't fix the treble. Weird huh?
Keep the lead from the wiper of the treble pot *well* away from the MV connections on the board and the connection to pin 6 of the PI - the layout shows these right next to each other which is a bit poor, IMHO.
Better to run the treble pot connection 'round the back of the PI. Make sure the MV connecting wires aren't laying alongside C11 (0.022uF).
£0.02
Re: New user, first build, almost works!
Everything you just said is part of my problem. When I read this, I started rearranging. The more I rearranged, the better things got. I reached a point where I had all sorts of leads looping through the air like McDonalds arches at,bar rush. I found I had SOMETHING messed up with the MV, by gently tugging on the outside wiper, I was able to get the MV to behave differently. Probably by moving the wires away from all those places you just told me to check.Tillydog wrote:Maybe.Trapland wrote:Anyway, disconnecting the presence still doesn't fix the treble. Weird huh?
Keep the lead from the wiper of the treble pot *well* away from the MV connections on the board and the connection to pin 6 of the PI - the layout shows these right next to each other which is a bit poor, IMHO.
Better to run the treble pot connection 'round the back of the PI. Make sure the MV connecting wires aren't laying alongside C11 (0.022uF).
£0.02
Here's what happened. By tugging on and eventually repositioning the outside wiper n the MV, the MV NO LONGER goes from quiet to really loud. The coarseness in the tone is better. The amp is quieter. The TREBLE CONTROL IS WORKING PERFECTLY. Basically,the amp was sounding And feeling so good that I couldn't stop playing. I ended up running out of time and didn't get everything done. I am replacing the MV leads with pairs of shielded wire like they should be.
I'll get back once its buttoned up!
Re: New user, first build, almost works!
Glad you're making progress
Good luck.
Just a comment: You can reduce cross-talk and feedback between wiring by running it tight against the (grounded) chassis, rather than up in the air - a bit like a half shielded cable, I suppose...Trapland wrote:I reached a point where I had all sorts of leads looping through the air like McDonalds arches
Good luck.
Re: New user, first build, almost works!
Sure.... It's only up in the air so I could listen as I pulled wire around with my chopstick.Tillydog wrote:Glad you're making progress
Just a comment: You can reduce cross-talk and feedback between wiring by running it tight against the (grounded) chassis, rather than up in the air - a bit like a half shielded cable, I suppose...Trapland wrote:I reached a point where I had all sorts of leads looping through the air like McDonalds arches
Good luck.
The real problem I'm having is the chassis is really tight, and I can't seem to both put things where I need them and keep them short while I put the board in place.
Anyway, today I hope to finish it.
Re: New user, first build, almost works!
Glad to see your finally taking my MV advice.
Re: New user, first build, almost works!
Well I managed to get everything working 100% except the presence control. The treble and presence squealing was solved by rerouting AND 1reversing the OT secondary. Everyone here told me to check it, but I had convinced myself that it was either a full power honk or nothing and I only had subtle feedback. Well anyway, all that is fine now.
The only other thing is I can't seem to get the presence control to do anything!
I've tried both the spec'ed version from the schematic and a JTM style and I just CAN'T hear anything when I turn it. That the only thing left to fix before I can show my friends my first build. I can't be making excuses while they play it.
Teleguy61: I thought you said something about the presence that was an issue for you. Any suggests for me?
The only other thing is I can't seem to get the presence control to do anything!
I've tried both the spec'ed version from the schematic and a JTM style and I just CAN'T hear anything when I turn it. That the only thing left to fix before I can show my friends my first build. I can't be making excuses while they play it.
Teleguy61: I thought you said something about the presence that was an issue for you. Any suggests for me?
Re: New user, first build, almost works!
Well I managed to get everything working 100% except the presence control. The treble and presence squealing was solved by rerouting, using shielded on the PPIMV AND reversing the OT secondary. Everyone here told me to check it, but I had convinced myself that it was either a full power honk or nothing and I only had subtle feedback. Well anyway, all that is fine now.
The only other thing is I can't seem to get the presence control to do anything!
I've tried both the spec'ed version from the schematic and a JTM style and I just CAN'T hear anything when I turn it. That the only thing left to fix before I can show my friends my first build. I can't be making excuses while they play it.
Teleguy61: I thought you said something about the presence that was an issue for you. Any suggests for me?
The only other thing is I can't seem to get the presence control to do anything!
I've tried both the spec'ed version from the schematic and a JTM style and I just CAN'T hear anything when I turn it. That the only thing left to fix before I can show my friends my first build. I can't be making excuses while they play it.
Teleguy61: I thought you said something about the presence that was an issue for you. Any suggests for me?
Re: New user, first build, almost works!
After dinking around with the presence control as designed, and trying to get a Marshall style presence to work without changing too much near the phase inverter' I went nuts.... No matter what I tried there was no effect!
I finally tore it all out and replaced the presence control with a Vox style CUT control. The amp was ice pick bright anyway. It works great.
I set it at 8-10' for Les Paul humbuckers, 5-8 for strat and tele, and about 2-6 for a pickuped acoustic.
I'm liking my amp. Maybe I'll sell it and build another one.
I finally tore it all out and replaced the presence control with a Vox style CUT control. The amp was ice pick bright anyway. It works great.
I set it at 8-10' for Les Paul humbuckers, 5-8 for strat and tele, and about 2-6 for a pickuped acoustic.
I'm liking my amp. Maybe I'll sell it and build another one.