Classictone PT & 6G3

[BobL]

Heya -


I'm building a 6G3, and I'm using a Classictone 40-18028 PT, which I think should work well, but I wanted to confirm what wires I should be using since I have options.


The rectifier I have on hand is a GZ34/5AR4, and looking at the sheet for the PT, it looks like using the Red/White wires should give me about the B+ I want with this amp:


http://www.classictone.net/40-18028.pdf


https://el34world.com/charts/Schematics/files/Fender/Fender_deluxe_6g3.pdf


But I have two questions:


1. Would I be better off using the red wires and getting a 5U4GB, which puts me right at the 375VDC, theoretically, or is this not going to matter that much?


2. I understand that I would use both red/white wires, and the red/yellow wire w/ the GZ34... but what are the red/blue and green/yellow wires? I'm assuming I just tape them off, but... what would they be used for?


Thanks for any help!

[Latole]

with GZ34/5AR4 =406 volts
With 5U4 = 375 volts
IMO amp will work fine with both voltage. More gain with 406 volts ?


Red/Blue ; bias voltage with red/ white. You can use it or leave it not connected with insulation and do bias circuit wiring as schematic
Green/ yellow ; heater center tap to ground; it is a must

[d95err]

A few percent more or less voltage will not make any significant difference. You will probably get just as much difference from variations in wall voltage, differences in rectifier tubes, etc. I'd keep the rectifier tube and use the 600V option (red/white). Start from there and then experiment with different rectifier tubes and the higher voltage winding if you want.

Red/Blue is a tap that can be used for the bias voltage. Not necessary in for the 6G3, as it taps the bias voltage directly off the HT. You can just tape it off.

Green/Yellow is the center tap for the heater voltage. It should be grounded (as shown in the schematic).

[BobL]

A few percent more or less voltage will not make any significant difference. You will probably get just as much difference from variations in wall voltage, differences in rectifier tubes, etc. I'd keep the rectifier tube and use the 600V option (red/white). Start from there and then experiment with different rectifier tubes and the higher voltage winding if you want.

Red/Blue is a tap that can be used for the bias voltage. Not necessary in for the 6G3, as it taps the bias voltage directly off the HT. You can just tape it off.

Green/Yellow is the center tap for the heater voltage. It should be grounded (as shown in the schematic).

Oh, duh on the heater CT.

with GZ34/5AR4 =406 volts
With 5U4 = 375 volts
IMO amp will work fine with both voltage. More gain with 406 volts ?

That's if I use the 660V option... I was going to use the 600.

Since they are already supposed to be pretty gainy amps, I'm trying to skew towards more clean headroom in general until I see how it sounds.


Thank you both!

[HotBluePlates]

I'm building a 6G3, and I'm using a Classictone 40-18028 PT ...

The rectifier I have on hand is a GZ34/5AR4, and looking at the sheet for the PT, it looks like using the Red/White wires should give me about the B+ I want with this amp ...

1. Would I be better off using the red wires and getting a 5U4GB, which puts me right at the 375VDC, theoretically, or is this not going to matter that much?

with GZ34/5AR4 =406 volts
With 5U4 = 375 volts

That's if I use the 660V option... I was going to use the 600.

Since they are already supposed to be pretty gainy amps, I'm trying to skew towards more clean headroom in general until I see how it sounds.

If you don't play the amp loud, it's not "gainy."  But if you don't want gainy you probably should look to a different amp, as there's quite a bit of harmonic action in this amp due to the preamp design.  More so than voltage, you'd need to change that to change the amp.

FWIW, I own a 1962 Deluxe and use to also have a '63 Deluxe.  Using the GZ34 noted on the tube chart and 117vac from a variac (which yielded 6.3vac on the heaters), I measured 405vdc on the 6V6s.

Experiment to find which taps & rectifier perform the way you like.  But if you are seeking to duplicate the original amp, they actually had voltage higher than shown on the schematic (though I don't have solid info on the earliest 6G3 amp voltages).

[BobL]

If you don't play the amp loud, it's not "gainy."  But if you don't want gainy you probably should look to a different amp, as there's quite a bit of harmonic action in this amp due to the preamp design.  More so that voltage, you'd need to change that to change the amp.

FWIW, I own a 1962 Deluxe and use to also have a '63 Deluxe.  Using the GZ34 noted on the tube chart and 117vac from a variac (which yielded 6.3vac on the heaters), I measured 405vdc on the 6V6s.

Experiment to find which taps & rectifier perform the way you like.  But if you are seeking to duplicate the original amp, they actually had voltage higher than shown on the schematic (though I don't have solid info on the earliest 6G3 amp voltages).

Yeah, I have a good idea of what I'm getting into with the amp gain wise, just saying that if I make any decisions that affect gain one way or the other, I'll likely skew towards clean just because I know it's a dirtier amp.  The two builds I use the most currently are a Princeton Reverb for home/studio and a Super 2x12 for live, and the super in particular is so clean, I thought it'd be fun to do something different with this build. I'm hoping I have a useable combo of gain/volume that I could play with the band, but we'll see how that turns out.  This one will also be a 2x12, and I'm going to start with a pair of Celestion Blues, which should give me a bit more volume/headroom, and playing my other F style amps into a UA OX (so I can rock out late at night) at home, I've found I really like the combo of those circuits w/ those speakers, so we'll see how that goes. I've used P12Qs in the others, and those are at the other end of the spectrum in terms of volume at something like 94db vs 100db, which lets me push the Super a bit more than I would with a louder speaker (though even then, I have that thing turned down pretty far to get to a useable band volume).

My dream is to ABY the Super & the 6G3 for clean/dirt, but my reality is I probably ain't gonna wanna carry that much crap around... also the 6G3 might be too loud when dirty? Guess I'll just have to see.

[BobL]

I was planning to add an adjustable bias to this circuit... what I'm planning to do is the following (sorry, bad drawing):





Should this be ok, or would I want to adjust some values?  Seems like I might need to play w/ the resistor value on the pot, but I wasn't sure about the cap...

[HotBluePlates]

I'm guessing the 22kΩ oughta be a little smaller (18kΩ?) so you've got a little range above & below the original amount of bias.

I know the location is traditional, but you may want to move the bias pot to a certainly-accessible spot.  I've had vintage Fender amps where that 10kΩ pot couldn't be used with the chassis in place because the speaker basket was in the way.

Bias is d.c. so there's probably no reason you couldn't move the adjustment to the back panel if you want.

[BobL]

I'm guessing the 22kΩ oughta be a little smaller (18kΩ?) so you've got a little range above & below the original amount of bias.

I know the location is traditional, but you may want to move the bias pot to a certainly-accessible spot.  I've had vintage Fender amps where that 10kΩ pot couldn't be used with the chassis in place because the speaker basket was in the way.

Bias is d.c. so there's probably no reason you couldn't move the adjustment to the back panel if you want.

It's actually going into a tweed style chassis, so I'll be accessing the pot from the inside w/ the back panel removed.


Looks like the next step down I have is 15K... might try that out to start.

[sluckey]

Looks like the next step down I have is 15K... might try that out to start.

I'd do that. Then adjust the 100K up/down for the correct bias range if not there already.

[BobL]

Looks like the next step down I have is 15K... might try that out to start.

I'd do that. Then adjust the 100K up/down for the correct bias range if not there already.

Got everything rolling - voltages look pretty ballpark - generally a bit higher than the schematic, but I think that's to be expected, yeah? I'm getting a signal, and it mostly seems musical and amp like, but:


Couple issues:


1. I'm getting an oscillation. I've tried reversing the brown/blue from my OT, but didn't seem to help. It does speed up as I increase the speed of the tremolo, but is always there.
2. I'm blowing lightbulbs for some reason... related? Crappy lightbulbs?
3. Amp is possibly quiet... it's late, so I have it plugged into an OX instead of an actual speaker cabinet, and signal seems quiet compared to what I'm used to with a Princeton into this box... until one time I turned it on and it was much louder, and kinda fuzzy.  When I touched the MM probe to the OT CT connection to the board, the volume instantly dropped again.
4. Tubes are cooking pretty good - bias seems to be 39/37 on each tube, and I can't go lower - I've got the 15K on the bias pot. Do I want to try to lower that, or do I want to lower the 100K resistor? I'm getting 387/388 at the plates.


EDIT: Yeah, the volume is definitely higher until I probe stuff on the board... this time I just was touching things with a chopstick, and just moving a wire coming from the grid of V4 dropped the volume, though moving that wire around in general was creating no strange noises at all...


Any guidance on things to check next? I've traced the wiring vs the layout, and it *seems* I have everything in place as it should be...

[BobL]

1. If I install a footswitch and turn it off, the oscillation leaves... so I guess that means that w/ the trem all the way down, the trem is still on, and that is probably the issue? I'm trying to understand how the pedal control for the trem works so that I might just replace the pedal, which I'll never use, with a switch on the front panel... would I just have a switch that goes to ground in one direction, and is open in the other direction?
2. I'm blowing lightbulbs because somehow I ended up with 3.2v lightbulbs.
3. Amp is for sure very quiet if I touch those wires going to the grids, so maybe I have a bad joint or something... looking into that.

[HotBluePlates]

1. I'm getting an oscillation. I've tried reversing the brown/blue from my OT, but didn't seem to help. It does speed up as I increase the speed of the tremolo, but is always there.

Do you mean "pulsing background noise"?

Both vintage 6G3 Deluxe amps I had did that.  There might be a way to fix it (search "6G2 Princeton tremolo" on this forum), but I haven't bothered trying to alter mine because it doesn't bother me.

1. If I install a footswitch and turn it off, the oscillation leaves... so I guess that means that w/ the trem all the way down, the trem is still on, and that is probably the issue? I'm trying to understand how the pedal control for the trem works so that I might just replace the pedal, which I'll never use, with a switch on the front panel... would I just have a switch that goes to ground in one direction, and is open in the other direction?

There is a wire that goes to the Trem Footswitch jack.  Run that wire instead to one lug of a single-pole single-throw (SPST) switch.  Connect the other lug of the switch to the ground of V2 Pin 8's 2.7kΩ cathode resistor.

All the footswitch is doing is grounding the signal at the grid of the trem oscillator (V2 Pin 7) so that it can't oscillate.

4. Tubes are cooking pretty good - bias seems to be 39/37 on each tube, and I can't go lower - I've got the 15K on the bias pot. Do I want to try to lower that, or do I want to lower the 100K resistor? I'm getting 387/388 at the plates.

You would make the 100kΩ smaller, to get more negative voltage available (less dropped across the 100kΩ).

FWIW, my 6G3 is biased at 30mA at 407v plate & screen.  It's normal to run these near 12w (or 100% if you go by older 6V6 ratings).

[BobL]

The volume thing is strange... I retouched the solder joints that I was able to get the drop to happen by touching (or touching wires attached to them), and that made no difference...


One thing I did notice, though, is that it tends to start out loud, then drop... and then when I turn the amp *off*, if I'm still making noise, it has a very large jump in volume (up) just before the signal cuts out.


This seems very strange.

[HotBluePlates]

Are the sockets new, or re-used from something else?  Do the make firm contact with the pins, or are the tubes wobbly?

The symptom sure sounds like a partial, or high-resistance contact that become good contact, and then you get full volume.

[BobL]

Are the sockets new, or re-used from something else?  Do the make firm contact with the pins, or are the tubes wobbly?

The symptom sure sounds like a partial, or high-resistance contact that become good contact, and then you get full volume.

Sockets are new, seem pretty firm to me.


Here is audio of what is going on:


http://www.boblefevremusic.com/temp/6G3/6g3_volume_drop.mp3


 - I turn the amp on, it is loud (though maybe fuzzier than it should be? I haven't played one of these before, so maybe this is just how fuzzy it is - volume is at about 50% here), then if I tap the amp literally *anywhere*, it experiences the volume drop.  In this case, I lightly tapped V5 w/ a plastic marker, but I've had the same result from tapping literally anything on the amp, including the chassis, or if I try to probe any contact from the cap board to the main circuit board, instant drop... which is making me wonder about the potential of a bad cap on that board? Like just a little bit of a discharge is enough to drain the cap or something... I'm not sure. At the very end, I hit a note and then turn the amp off, and you can hear the volume temporarily bump back up.  All of the above can be consistently reproduced.

It's going to be really difficult to get to that cap board... it's under a pan on the back of the chassis and the screws holding it in place are under the main circuit board... which... as I did it, I thought 'maybe I'm causing a future headache here'.  Should I try to get at that board? I'm kind of thinking I don't actually need the pan over that cap board since it'll be buried inside the cabinet, but maybe that's not a good idea either since there are 350-400v at those connections.  In retrospect, I could've sandwiched the chassis between a nut on each side of that screw so I could remove the pan from the outside.  Hindsight, 20/20 and all that.

[sluckey]

Just use self-tapping screws for the doghouse. Leo did.

[BobL]

Just use self-tapping screws for the doghouse. Leo did.

Yeah, the question at this point is 'Can I get this off of there w/o removing the controls and the board?'


Answer is... maybe, though then I would have to do something like self tapping screws to get it back on there, so that's a good option.


Do you think that's my next step? Test those caps?

[BobL]

Answer is... maybe, though then I would have to do something like self tapping screws to get it back on there, so that's a good option.

Answer is... 'No'.  I'm going to have to pull the board and controls to get to those screws. Damn.

[BobL]

Ok, progress... got the cap pan off of there w/o too much trouble (though I ended up shorting the tone and volume knobs on the bright channel when I put it back together and didn't notice for a while.


I found a bad joint, fixed that, and volume is now high and steady.


Amp is incredibly dirty... to the point of sounding like I have an overdrive in front of it, which surprised me, as I knew it to be a dirtier amp, but this seems beyond what I've heard from others.  Maybe I'll play around with tubes, maybe an 12AT7 in V3?  I guess I could bias colder? What would going to a rectifier that put out less juice do for me, do you think?


Other issue is that with the vibrato on, the intensity knob has a pulsing squeal if I turn it up past about 8 o'clock. Wondering what a good way to approach that would be so that I can have a more useable range on the trem?

[sluckey]

Have you verified the NFB phase is proper?

[Mike_J]

Just use self-tapping screws for the doghouse. Leo did.

Fender ground the point off the screws. I have done it with an inexpensive grinder with a diamond blade and it is like an original Fender screw in no time. They are either 8s or possibly 10s. They are also pretty short length to start with.

[sluckey]

Just use self-tapping screws for the doghouse. Leo did.

Fender ground the point off the screws.

I doubt that. I'm talking about using self tapping machine screws, not sheet metal screws. They look like this and will actually cut threads as you drive them in...

https://www.ebay.com/itm/Screw-self-tapping-6-32-1-2-in-long-Steel-100-pcs/293481024564?hash=item4454d50c34:g:A-0AAOSw6WJeTCvH

[BobL]

Have you verified the NFB phase is proper?

I guess I'm not sure how to do that?


I played around with tubes, and putting a 12AY7 in V3 sounds really nice, and seems to tame the squealies on the trem as well.


Quick demo of a couple sounds... all tele, neck w/ the volume rolled off a bit, bit of the trem, then tele bridge chords, then tele bridge lead w/ some echoplex. Bright channel w/ the volume at about 2 o'clock, tone at... 9:30? Nighttime, so running into a UA OX w/ their AC30 cab, since I'm planning to put this in a tweed cab w/ a couple Celestion Blues.


http://www.boblefevremusic.com/temp/6G3/6g3_demo.mp3


Sounds pretty good to me... the Normal channel is kinda underwhelming... I wonder what I could do to make that a cleaner channel. Seen other things, like the Down Brownie doing more of a 1987X channel on that one, though still pretty dirty... hrm...


Fun little project, though.

[HotBluePlates]

I found a bad joint, fixed that, and volume is now high and steady.

Congrats!!  It's often hard to find that needle in the haystack, especially when you feel like everything you look at appears correct.

I played around with tubes, and putting a 12AY7 in V3 sounds really nice, and seems to tame the squealies on the trem as well.

I wonder if you simply have a microphonic tube, as V3 is solely the phase inverter.

Quick demo of a couple sounds... all tele, neck w/ the volume rolled off a bit, bit of the trem, then tele bridge chords, then tele bridge lead w/ some echoplex. Bright channel w/ the volume at about 2 o'clock, tone at... 9:30? Nighttime, so running into a UA OX w/ their AC30 cab, since I'm planning to put this in a tweed cab w/ a couple Celestion Blues.

Sounds great!!  Speakers make a big difference, especially in what they enhance vs shave-off.  It would be interesting to see where you land when you try the amp with an actual cabinet.

Sounds pretty good to me... the Normal channel is kinda underwhelming... I wonder what I could do to make that a cleaner channel. Seen other things, like the Down Brownie doing more of a 1987X channel on that one, though still pretty dirty... hrm...

Well, the Normal channel is exactly the same as the Bright channel, but with a bit of high end rolled-off at the input stage at the plate load.  This amp is really a "1-channel amp" though I suppose it was a selling point in the 50s & 60s to be able to have several players plug into a single amp.

Amp is incredibly dirty... to the point of sounding like I have an overdrive in front of it, which surprised me, as I knew it to be a dirtier amp, but this seems beyond what I've heard from others.  ...

There are a bunch of "speaker cab boxes" onstage in the video below, but look closely at the right-corner of the drum riser.  See what kind of amp Rev. Billy G is playing through on this live TV performance...

[bmccowan]

incredibly dirty

Nice work! I am surprised that you find it incredibly dirty. Of course, that is all subjective. I built one several years ago. It does not do blackface clean, but it is cleaner than a 5E3. You say that it is dirtier than others you have heard. So before modding, you may want to go through and check everything.
The following thread includes an interesting back and forth between Rob Rob and the builder.
https://www.tdpri.com/threads/rob-inspired-6g3-looking-for-feedback.803834/

[BobL]

I wonder if you simply have a microphonic tube, as V3 is solely the phase inverter.

Maybe? I played around with that tube in different places, and in all instances adding it to the mix seemed to clean up that squeal. I wasn't really paying attention to which of the three 12AX7s I was swapping in went where in the end.  When I was tapping through tubes I wasn't getting noise on any of them, but yeah, I don't know.  I thought I had a 12AT7 here as well, but I don't, so I might order one of those as well as a 5U4GB and see how I like those tubes thrown in to the mix. 

Sounds great!!  Speakers make a big difference, especially in what they enhance vs shave-off.  It would be interesting to see where you land when you try the amp with an actual cabinet.

Yeah, the cab my super is in is the same cab with P12Qs, so I thought it'd be fun to swap the amps between the two cabs and see which speakers I liked with which amp.

Well, the Normal channel is exactly the same as the Bright channel, but with a bit of high end rolled-off at the input stage at the plate load.  This amp is really a "1-channel amp" though I suppose it was a selling point in the 50s & 60s to be able to have several players plug into a single amp.

Right - just that one cap... that's why I was thinking something a little different over there could be cool?

There are a bunch of "speaker cab boxes" onstage in the video below, but look closely at the right-corner of the drum riser.  See what kind of amp Rev. Billy G is playing through on this live TV performance...

Yeah, hearing that a lot of early ZZ Top was this amp intrigued me, for sure. Also, they need to tune. :)


Thanks for all the help!

incredibly dirty

Nice work! I am surprised that you find it incredibly dirty. Of course, that is all subjective. I built one several years ago. It does not do blackface clean, but it is cleaner than a 5E3. You say that it is dirtier than others you have heard. So before modding, you may want to go through and check everything.
The following thread includes an interesting back and forth between Rob Rob and the builder.
https://www.tdpri.com/threads/rob-inspired-6g3-looking-for-feedback.803834/

Yeah, I'll have to try it with actual speakers and see how loud it is in the room, but in my clip above it's getting pretty dang saturated.  I checked a couple clips, as well as listening to that ZZ clip, and maybe mine is about as dirty as the others. Always different to play one vs hear someone else play one too, I suppose.

[Mike_J]

Just use self-tapping screws for the doghouse. Leo did.

Fender ground the point off the screws.

I doubt that. I'm talking about using self tapping machine screws, not sheet metal screws. They look like this and will actually cut threads as you drive them in...

https://www.ebay.com/itm/Screw-self-tapping-6-32-1-2-in-long-Steel-100-pcs/293481024564?hash=item4454d50c34:g:A-0AAOSw6WJeTCvH

Attached are a picture of an old fiber board for a Fender Vibroverb amp and the fiberboard backing used to back the board with the eyelets on it and insulate the circuit board from the chassis. Similar boards were used under the dog house on the other side of the chassis to hold the ecaps. I bought this board and the chassis that went with it and also a board and chassis for an AB763 build I did. When I removed their boards from their chassis they had screws flattened on the ends. I imagine Fender had them made this way and didn't have some poor shlub with a grinder removing the points off screws all day.


I have also attached a picture of a rounded over machine screw. This screw doesn't look like a Fender screw. It is probably one I ground the point off of myself for the same reason Fender did. I have a 1/2" standoff on my main board. Any part of a screw that goes through the chassis and into air can short a component on the board if it touches it. Additionally, air makes a terrible connector for a screw. Any part of a screw that is not connected to metal on a chassis isn't doing a thing. If it had a point on it and the fiberboards are flush to the chassis as Fender had them a sharp screw would make it possible for perforation of the fiberboard that is acting as the insulator for their respective boards.


I didn't discuss this matter with Leo so I am not positive that what I said above is the actual reason they used rounded over machine screws but I have seen nothing but rounded over screws in the small sample of screws I have removed from old Fender chassis. I would bet the farm they drilled the holes and used the screws I mentioned. I am only mentioning this to advise people that any screws from a dog house board going through the chassis and any screws going from the chassis into the dog house should be short and rounded over. Especially if they want to go old school, for reasons unknown to me, and use fiberboard against the chassis like Fender did.

[Mike_J]

My apologies to sluckey if my last post seemed abrasive. I have immense respect for your knowledge and advice. I believe the main difference between man and ape is man's ability to use fasteners. I take fasteners more seriously than I should.


Sincerely
Mike

[BobL]

I believe the main difference between man and ape is man's ability to use fasteners. I take fasteners more seriously than I should.

I wonder if I can find 'attractive' self tapping screws at the local hardware store... maybe not...


Man's ability to use fasteners separates them from apes... and hobbiest amp builders' level of concern about the aesthetic concerns regarding parts of an amplifier that literally 3 people will ever look inside separates them from man. ;)

[sluckey]

Attached are a picture of an old fiber board...

Not talking about boards. Bob used a 1/8" G10 board mounted on standoffs. His problem is that he mounted the DOGHOUSE to the chassis using machine screws and nuts. Then he mounted the board which blocked access to the doghouse screws making it very difficult to remove the doghouse to gain access to the filter caps. My suggestion was to use self-tapping machine screws to attach the doghouse to make it very easy to remove the doghouse. Of course he could use sheet metal screws to attach the doghouse but IMO, machine screws look better.

[Mike_J]

Attached are a picture of an old fiber board...

Not talking about boards. Bob used a 1/8" G10 board mounted on standoffs. His problem is that he mounted the DOGHOUSE to the chassis using machine screws and nuts. Then he mounted the board which blocked access to the doghouse screws making it very difficult to remove the doghouse to gain access to the filter caps. My suggestion was to use self-tapping machine screws to attach the doghouse to make it very easy to remove the doghouse. Of course he could use sheet metal screws to attach the doghouse but IMO, machine screws look better.

I understand. But any screw that is long enough and goes through the chassis can impact components on the board, standoff or not. A self-tapping screw would probably go right through the G10. My comments were just a suggestion using a good method of reducing the likelihood of it being a problem. I guess if you are impatient and want to live on the wild side you could use your self-tapping screws.


Not to stray too far from the subject but Doug's store has a great selection of short screws you can't buy anywhere else in quantities less than you would use in five lifetimes and associated kep nuts. Everyone that builds amps should own at least 25 of each size especially for easy installation of some standoffs. Might have to cry uncle here though. Noticed Doug has self-tapping screws that look like the screws Fender used. Think you would have to drill a smaller pilot hole though to get them started so they are not the type of self-tapping screws I was thinking you were going to use.

[PRR]

> A self-tapping screw would probably go right through the G10.

Did you look at the 'self-tapping screw' link?



Seems unlikely these noses would pierce fiberglass without a pilot hole.

[Mike_J]

> A self-tapping screw would probably go right through the G10.

Did you look at the 'self-tapping screw' link?



Seems unlikely these noses would pierce fiberglass without a pilot hole.

Agreed. Looked at Doug's site and he has self-tapping screws that are just like the screws Fender used. If Doug's self-tapping screws are used I have no problem with them whatsoever. In fact I am sure I purchased some of them in the past and just forgot about it. Placed an order yesterday, wish I had included them in the order. The ends of my screws kind of look like some shlub with a grinder rounded them off. I will be replacing them with some screws that Doug sells.

[bmccowan]

Fender and others used those screws for many tasks, including tube sockets. I keep 4, 6 and 8 size in several different lengths on- hand. Drill the right size hole and they work great!

[HotBluePlates]

... I built one several years ago. It does not do blackface clean, but it is cleaner than a 5E3. You say that it is dirtier than others you have heard. ...

Yeah, I'll have to try it with actual speakers and see how loud it is in the room, but in my clip above it's getting pretty dang saturated.  I checked a couple clips, as well as listening to that ZZ clip, and maybe mine is about as dirty as the others.

My '62 Deluxe is dirtier when playing clean than my 5E3 Deluxe clone.  I think you really hear the 220kΩ & shared 1.5kΩ contributing harmonics early.

The original 12K5-3 Oxford is also brighter & crunchier than a comparable 60s Jensen or Celestion speaker.  You might not believe it at first, but 60s Celestion Blue or Silver alnico speakers are darker than the brown Deluxe's Oxford.

Quick demo of a couple sounds... all tele, neck w/ the volume rolled off a bit, bit of the trem, then tele bridge chords, then tele bridge lead w/ some echoplex. Bright channel w/ the volume at about 2 o'clock, tone at... 9:30? Nighttime, so running into a UA OX w/ their AC30 cab, since I'm planning to put this in a tweed cab w/ a couple Celestion Blues. ...

The clip below is my '62 Deluxe plugged into a 2x12 cab with a pair of 1965 T1088 Celestion alnico silver speakers.  Just a cell phone clip, but it sounds true to the way the amp sounded in person.  Bright channel, Volume turn up to ~9:30 and Tone maybe 1-2:00.

https://soundcloud.com/hotblueplates/6g3-t1088

Same amp, same settings played through the on-board Oxford:

https://soundcloud.com/hotblueplates/6g3-oxford

Same amp, same settings but through a 1964 Jensen C12PS:

https://soundcloud.com/hotblueplates/6g3-c12ps

So you'd expect old Celestion alnico speakers to tame some of the treble-fizz.  These clips are done with a home-brew Tele with both pickups on.  It is kind of a mid-focused guitar, but with a tendency towards emphasizing a lot of string-harmonics.  To calibrate what you're hearing, below is the same guitar and about the same room-volume played through a '62 Ampeg Reverberocket and a '67 Super Reverb (the SR is set with Bass ~1-2, Mid full-up, and Treble ~5).

https://soundcloud.com/hotblueplates/poor-side-ampeg-rr

https://soundcloud.com/hotblueplates/poor-side-super-reverb

[Mike_J]

> A self-tapping screw would probably go right through the G10.

Did you look at the 'self-tapping screw' link?



Seems unlikely these noses would pierce fiberglass without a pilot hole.

Last comment I am going to make about this and I apologize for getting carried away on his thread. Took a picture of the screw I was thinking of when I read sluckey's comment. It is self-piercing an inch long and would go through most things inside an amp chassis. Getting to the age where when something gets in my head it kind of gets stuck in there. The self tapping screws Doug sells in his store are just like the screws Fender used. Didn't even think of those as the screws sluckey was probably thinking of. I was thinking poor BobL he is going to use an inch long self-piercing screw to attach his dog house. The damage that could do. Anyway BobL I apologize for getting carried away on your post.

[BobL]

No need to apologize. Most conversations I start inevitably end up being about screwing in the doghouse.