102 as Lowplate Classic

[Charlie Wilson]

Good one Aaron. Just a reminder with power tubes(in a 100w), It is not important that each tube is matched but that the pair on one side is matched to the pair on the other side. If you find yourself with some slightly mismatched tubes sometimes you can swap them around so that you get each pair pretty close. It will probably take a bit for your PI tube to settle in so you may have to readjust a couple more times.
CW

[aflynt]

Thanks Charlie! That's pretty much exactly what I did. Two of the power tubes in there were pretty close and I found another pair laying around that were fairly close too. I just put one from each set on each side. The PI tube should be pretty stable as I had it in another amp for awhile.

-Aaron

[Structo]

I thought something was wrong when the presence pot on my 100w was scratchy.

It's normal.

There is a way to wire it so it doesn't make that noise but I think that is a departure from the ODS design, so I just left it be.

Since it isn't frequently adjusted, it isn't a problem.

When I first built it and was adjusting things, like the PI trimmer, I didn't really hear much change.
If I recall, I have a GE long plate 12ax7 there.
What happens is the caps on the PI output cause a bit of time delay when you adjust the trimmer.

What value plate resistors did you use on the PI?

[aflynt]

What value plate resistors did you use on the PI?

I believe I have 124k and 113k Mepco Electra MF7Cs in there right now with a 10k trimmer. I didn't hear nearly as much of a change when adjusting the PI trimmer on any of my #102 Highplate Skyliner builds oddly enough.

-Aaron

[aflynt]

More clips. Tele bridge pickup. Higher gain. The HF taper trimmer is down to 115k now.

https://soundcloud.com/aflynt/help-the-poor
https://soundcloud.com/aflynt/lowell-groove
https://soundcloud.com/aflynt/how-long-blues

How long blues is a bit more visceral with the tone on the guitar all the way up and a bit higher gain on the amp. I think it's got a cool Roy Buchanan kind of vibe set like that. Help The Poor is same higher gain amp settings with tone rolled off a bit. Lowell Groove is a bit lower gain on the amp.

I'm thinking that this iteration could really use an OD tone control (HF Taper trimmer pot on the front panel). Another idea I was playing around with was a dual 100k OD Level pot with the second pot set up as a reverse HF Taper trimmer. So Ratio feeds fixed 68k in series with 100k pot set up as fixed resistor feeding .0012uF cap to ground. I was going to pop one in, but I'd need to trim some material off the PS board for it to fit.

-Aaron

[jam-mill]

More clips. Tele bridge pickup. Higher gain. The HF taper trimmer is down to 115k now.

https://soundcloud.com/aflynt/help-the-poor
https://soundcloud.com/aflynt/lowell-groove
https://soundcloud.com/aflynt/how-long-blues

How long blues is a bit more visceral with the tone on the guitar all the way up and a bit higher gain on the amp. I think it's got a cool Roy Buchanan kind of vibe set like that. Help The Poor is same higher gain amp settings with tone rolled off a bit. Lowell Groove is a bit lower gain on the amp.

I'm thinking that this iteration could really use an OD tone control (HF Taper trimmer pot on the front panel). Another idea I was playing around with was a dual 100k OD Level pot with the second pot set up as a reverse HF Taper trimmer. So Ratio feeds fixed 68k in series with 100k pot set up as fixed resistor feeding .0012uF cap to ground. I was going to pop one in, but I'd need to trim some material off the PS board for it to fit.

-Aaron

Aaron,

Really nice playing. Thought I was listening to RF! The tone, to my ears, is incredibly close. Very pleasing to listen to. Thank-You for sharing your efforts.

Regards,
-jack

[aflynt]

Aaron,

Really nice playing. Thought I was listening to RF! The tone, to my ears, is incredibly close. Very pleasing to listen to. Thank-You for sharing your efforts.

Regards,
-jack

Thanks Jack! I think it'd be even more in that vein with a guitar with full sized humbuckers. One of these days I need to get my hands on one.

-Aaron

[Charlie Wilson]

Nice clips Aaron. I have been experimenting with my Low Plate Classic. I think we have similar concerns with the circuit(OD a little on the thin bright side) and I am using a little different strategy to fatten things up a bit. First of all I used a 100k drive pot that measures on the high side, about 117k. That helped knock the highs down a little and fatten things up. I still didn't like the way the high end sounded with a Strat in OD, so in a moment of frustrations I guess, I took out the 330pf treble cap and replaced it with a .002. I was pleasantly surprised that the OD sounded much better, fatter with the Strat and still sounded good with the Les Paul. I think .002 may be a bit much so I think I will try .001 next but this is heading in the direction I like. My inspiration was the Jackson Browne(Carlos Rios?) amp with a mid boost. I thought maybe of doing a mid boost instead of the deep switch but I really like the Deep switch, so I am going to hopefully find a larger treble cap value that is not to over the top with mids. I also really like the .02 V1b coupler. I tried the .047 again just to remind me of what it sounded like and it sounded muddy.
CW

[dcribbs1412]

Really great sounding clips Aaron
thanks for the mod info. Going will try some of yours and Charlies tips
what is your recording setup?


Darin

[aflynt]

Nice clips Aaron. I have been experimenting with my Low Plate Classic. I think we have similar concerns with the circuit(OD a little on the thin bright side) and I am using a little different strategy to fatten things up a bit. First of all I used a 100k drive pot that measures on the high side, about 117k. That helped knock the highs down a little and fatten things up. I still didn't like the way the high end sounded with a Strat in OD, so in a moment of frustrations I guess, I took out the 330pf treble cap and replaced it with a .002. I was pleasantly surprised that the OD sounded much better, fatter with the Strat and still sounded good with the Les Paul. I think .002 may be a bit much so I think I will try .001 next but this is heading in the direction I like. My inspiration was the Jackson Browne(Carlos Rios?) amp with a mid boost. I thought maybe of doing a mid boost instead of the deep switch but I really like the Deep switch, so I am going to hopefully find a larger treble cap value that is not to over the top with mids. I also really like the .02 V1b coupler. I tried the .047 again just to remind me of what it sounded like and it sounded muddy.
CW

Thanks Charlie!

I'm pretty happy with the sound of the amp overall, though I kind of took the easy way out by using the HF taper. The only thing I don't like is that the OD channel sounds better at low drive settings with less taper and better at high drive settings with more taper. That's why I had the idea of the dual pot where as you turned up the drive you'd get less resistance in the filter circuit. I think the trick would be dialing in just the right range, though.

I don't think I'd like the higher treble cap as the amp already seems to have more mids than I need. I usually engage the deep and pull the mid pot way back (like 8-9:00).

-Aaron

[aflynt]

Really great sounding clips Aaron
thanks for the mod info. Going will try some of yours and Charlies tips
what is your recording setup?


Darin

Thanks Darin!

My recording setup is an SM57 into a Focusrite Scarlett interface into Garage Band on my Mac.

-Aaron

[Charlie Wilson]

Ok, now I am curious. I keep chickening out on trying a larger than 100k trimmer mainly because the old timers(Gil,Tony) seem to not like it. Aaron can you describe what the sonic effect in terms of treble, mids, and bass was when you upped the trimmer. Maybe #124 had the 346k trimmer before the Skyliner conversion.
CW

[aflynt]

Ok, now I am curious. I keep chickening out on trying a larger than 100k trimmer mainly because the old timers(Gil,Tony) seem to not like it. Aaron can you describe what the sonic effect in terms of treble, mids, and bass was when you upped the trimmer. Maybe #124 had the 346k trimmer before the Skyliner conversion.
CW

More lows in the OD really. Going from 5uF to 10uF cathode bypass on V1 added more beef than the trimmer I think, though maybe it just evened them out. I did both at the same time. HF Taper definitely has a bigger effect on smoothing out the OD. Personally, I'd just do whatever your ears tell you your amp needs. They're all different.

This amp is really growing on me. I dig that high end 'whistle' I'm getting with the tele too. It's actually darker than my straight up #102s right now, but clearer at the same time. Doesn't crunch as well, though.

I think you're right (from that other #102 thread) about the old iron being pretty hit or miss. The amp I cannibalized for this OT was really nice sounding back when it was my main rig back in the '90s. This amp seems to sound good no matter what you do. Just different. I've had pretty good luck with Mercury Magnetics High Power Tweed Twin OTs too. Not quite as smooth, but still sweet and very beefy.

-Aaron

[Structo]

Sounds great!

Very Ford like.

[jam-mill]

Aaron,

Really nice playing. Thought I was listening to RF! The tone, to my ears, is incredibly close. Very pleasing to listen to. Thank-You for sharing your efforts.

Regards,
-jack

Thanks Jack! I think it'd be even more in that vein with a guitar with full sized humbuckers. One of these days I need to get my hands on one.

-Aaron

Now that you mention it, I've only ever played a Strat. Perhaps its time to try a guitar with HB's. I've got a 35-year old ES-335 (purchased new and never really played because I did not 'relate to' it).

-jack