The Eagle Supre - Big SE Amp

[RJ Guitars]

Sounds like mostly good news. I have been buried with other things but I did get a couple boards made for Zippy with eyelets instead of those turrets. I am just about convinced that you need a small solder gun to work with them. I cranked my iron on the last build and got the job done but I don't plan to buy any more of them for the future. Sometimes cheaper just is not better.

I may try a 12BZ7 in my Supre... I had kinda forgot about how much I liked them in a Champish circuit previously.

rj

[Berger]

I am tempted to buy the deal for staking my own turrents/eyelets. Depending where I endup I may need to make my own board which will be fun I'm sure.

I'll probably strip down the amp. I need to drill a hole for the 12pin socket. I also may add another 9pin another 12ax7 or similiar. Oh and a hole for a switch for the pt taps. I got a 6k6gt tube today too. I wonder if the lower voltage will keep that thing for redplating....

I'm sure I need more holes for pots....



Aaron

[RJ Guitars]

the 6k6gt is what they used in the Fender reverb unit so you can look at the voltages on that schematic and get an idea of what they were using there. I'll bet you could use it without any issues.

I am using modified arrow points for staking the turrets. They work perfect on the Keystone turrets but those seem to be a softer allow than the ones I used on the Eagle amps.

One thing I had in mind with these chassis was having a little extra room for mods, particularly extra tubes.

[Berger]

Thanks, I'll take a look at the schematic on my break today.

Ya,one of the reasons I wanted the kit because it looked like there was a lot of room to do mods

I'm definitely looking at either making my own board, or possibly getting a second board from you....time to go looking for parts I guess

Aaron

[Berger]

Got to work on the amp again tonight.
I took it apart and drilled two new pot holes and a hole for the 12 pin socket.

Got home and then put it back together. And it still worked.

1 of the 2 pots is for a 1meg pot for the negative feedback loop. Its also a push pull pot, so I can disconnect it fully if I wish. So far I like it, its not a dramatic change but its useful in my opinion.

The 2nd pot is for a master volume, I know some don't like them but I want to be able to crank the preamp If I don't like it I can move stuff around and maybe make it a mid pot.

I haven't wired in the triple triode tube yet. hopefully later in the week. Going to read up on biasing that tube tonight.

Did not get to try the 6k6gt tube tonight, but I did order a kt88

Aaron

[Berger]

negative feedback look wired in with shield cable, I think I'll pull/change r10 to give it more range.

Also I got the 6ac10 wierd in. Only 2 triodes with them directly tied to the 12ax7 pins. So you can put one or the other in without having to go inside the chassis.

What I'm wondering is if any one has any suggestions as to what to do with the extra triode? Put it before the tone stack? After the volume and before the original 2nd triode? after that triode?

I have some ideas, but I was wondering if anyone had any cool ideas?

I need to fire up the cam soon, and make you guys some clips

Aaron

[Berger]

here's an update with some pics inside the chassis.

I should probably trim down some of the wires at some point....

Aaron

[Zippy]

1 of the 2 pots is for a 1meg pot for the negative feedback loop. Its also a push pull pot, so I can disconnect it fully if I wish. So far I like it, its not a dramatic change but its useful in my opinion.

The effective range for the negative feedback loop is typically 22K-100K so your pot is likely only doing anything when really close to 0-1. I'd go with a 100K push/pull pot.

What I'm wondering is if any one has any suggestions as to what to do with the extra triode?

I've lost track. Did you already parallel V1? That'll give you a lil' gain plus some noise reduction.

[Berger]

The effective range for the negative feedback loop is typically 22K-100K so your pot is likely only doing anything when really close to 0-1. I'd go with a 100K push/pull pot.

That's what I've found as well. I've been looking for 100k push/pull like what I have now to no avail. Anyone see any problems using a normal push/push thats used in a guitar?

I've lost track. Did you already parallel V1? That'll give you a lil' gain plus some noise reduction.

I did the parallel with the 6ac10 tube and didn't notice too big of a difference...but I may have not done it correctly. I was going to add a parallel 12ax7 but I didn't drill a hole for it the last time I broke it down.

Currently I'm looking at doing a variation on the ax84 4-4-0 preamp since that has 3 triodes...but the books and schematics will be going with me this weekend so we'll see what comes out..

Thanks for your help and suggestions Zippy!

[Zippy]

That's what I've found as well. I've been looking for 100k push/pull like what I have now to no avail. Anyone see any problems using a normal push/push thats used in a guitar?

What's "normal"? If it's 500k, that's still too large.

[Berger]

That's what I've found as well. I've been looking for 100k push/pull like what I have now to no avail. Anyone see any problems using a normal push/push thats used in a guitar?

What's "normal"? If it's 500k, that's still too large.

normal meaning this style

http://www.ebay.com/itm/2-Push-Pull-Lin ... 27b92d7ca3

as opposed to this style

http://www.ebay.com/itm/CTS-1-Meg-Push- ... 2c58f63cc3

I'm saying the 'style' as opposed to the actual resistance values

Hopefully that makes sense....

maybe it makes more sense to ask if there is a voltage/wattage rating I need?

[Berger]

finally got around to recording some videos. Here is the first one

Gutiar is a Carvin ct4m middle position so both pickups on.
Cab is a custom out of red oak, has a carvin 12" 8 ohm british speaker
tubes are 12ax7 and a 6l6

I'll post more videos later with the 6ac10 tube,etc.

http://www.youtube.com/watch?v=votw4e1XfFs

Aaron

Edit: tone stack was at noon when engaged. I had the negative feedback loop disconnected in the clip.

[RJ Guitars]

Aaron,

Just back from a 3 day weekend in south Tejas... nice to see that part of the world get some rain after a very long drought!

Your thread has inspired a couple more guys to put together their own Eagle Supre builds... thanks for sharing your progress in the posts.

Your amp is sounding very good. I think it is immensely helpful to folks to get to hear some sound clips and get some sonic confirmation of the text that we write about these. If only getting a recording with decent tone was simpler we might get more clips out on these. I tend to struggle to capture the tone and not biff something when I record.

Great work, I appreciate the updates to thread. That 12 pin tube is very funky looking. When you paralleled the gain stage did you change the anode and cathode resistor values?

rj

[Berger]

Glad to hear some other guys will be building them too. It's been fun to see how other guys have modded them and I'm looking forward to what people do next.

Here is a video that is the same 6l6 power tube, but with the 6ac10. There isn't much difference at this point. I still need to use the third triode.
http://www.youtube.com/watch?v=NYDr90c9Dg8

And here is a video using the 6ac10, a jj el34, and my weber mini mass. I think it sounds pretty good cranked. The thing is really loud and thats about the only way for me to crank it right now.
http://www.youtube.com/watch?v=I_LCIEFOm3w

There are a bunch more videos with the different tubes. But a side from the last video I never really had the volume above 9 o'clock

I'm really thinking I need to put a master volume in it. I'm interested to see if I can get that preamp distortion.

I changed the plate resistors when I parallel it, but not the cathode resistors. I'm going to mod the wiring in a couple days which would allow me to change those without much trouble.

I hope everyone likes the clips..I never know what to play, and I try to play the same thing so 'hopefully' I can tell the difference in tubes in the clips if there is any...

Aaron

edit:
Also I think something gets lost on the point and shoot cam recording. to me the 6v6gt and the 6k6gt where not as bright as the other tubes. to me the kt88 was really bright..

[Berger]

mods for the night.

I added in the master vol from surfsup schematic of the mods he did. I like it. work well for me and what I'd like it to do.

I put a 2.2meg resistor across my negative feedback pot, which makes it a bit more usable...of course it only really does much when cranked...which is how they're suppose to be if I understand them correctly.

waiting for my terminal strips to get here so I can add in my 3rd triode...

Otherwise it's sounding good

Aaron