Bassman 5b6

[Colossal]

The Zolota layout uses a laydown PT and I used his OT orientation without thinking about it. Live and learn. I'm going to take this opportunity to try the headphone trick for OT orientation.

Set backs like that are annoying and they can wreck an OCD layout and your best intentions but they also do provide that growth opportunity by which you will ALWAYS pay attention to your PT/OT layout in the future. The amp looks really nice so far!

[rp]

Might try build a Standel 25L15 ...

FYI: http://www.el34world.com/Forum/index.php?topic=14263.0

Amazing build. Will either inspire or make you curl up in the corner and cry.

[telentubes]

I highly recommend the headphone trick. Hopefully you have enough slack in your OT leads so you can spin it if you need to. You may end up with a few extra bolt holes, but that's not a biggie if you end up with a quieter amp.
I'm looking forward to your first impressions of this thing once it gets fired up. Especially with the hefty iron.

[M Fowler]

Might try build a Standel 25L15 ...

FYI: http://www.el34world.com/Forum/index.php?topic=14263.0

Amazing build. Will either inspire or make you curl up in the corner and cry.

Nice build but I like the original Standell schematic.

[Matt D]

Thanks guys for the encouragement. I got the transformer flipped 90 degrees without having to lengthen any leads. The headphone trick bore out the fact that this was a good idea. I could have gotten it a little quieter by moving the OT over further but it would have been right up against the preamp tubes, and my intuition told me that might not be a good idea. I was hoping to get it finished up today but had to stay late at work. Tomorrow I'll put up some new pics whether I get it finished or not.

[Matt D]

More progress on my build documented over on the steel guitar forum. I have to figure out some low plate voltages on the preamp tubes.

http://bb.steelguitarforum.com/viewtopi ... 26#2043626

[Matt D]

Here are my voltages with the Zottola values in parentheses.

B+1: 406v (400v)
B+2: 348v (320v)
B+3: 323V

6l6 Plates: 405v (390v)
6l6 Screens: 348v (320v)
6l6 Cathodes: 27v (25v)

6SL7 Plates: 111v, 113v (216v)
6SL7 Cathode: 3.76v, 3.63v (2.5v)

6SC7 Plates: 134v (160v)
6SC7 Cathodes: 1.8v (2.0v)

I double checked all my plate load resistors with the schematic and all the values seem correct. Anybody see anything that I'm missing? The amp actually sounds ok as it but definitely breaks up way too much for steel. I also have some ghost notes around the 12th fret. Even with the way-off voltages the octal tubes have a nice sensitivity to variations in right hand technique. I'm going to triple check everything tomorrow and then start adjusting plate load resistors.

[Matt D]

Apologies for the poor photographs. I'll try and work on my technique and get something better up soon!

[M Fowler]

Matt you need to decrease the values of your dropping resistors to raise the voltages to the 6SC7 and 6SL7 tubes which will increase your headroom/gain.

Mark

[Matt D]

After rolling some preamp tubes I now have 200v on the 6sl7 and 142v on the 6sc7. That's only around 10% off from the Tino Z values. My original PI tube must have been bad. Any suggestions for how high I can/should go on the plate voltage for these tubes (other than the max plate voltages in the data sheets)? I have an old Heathkit decade resistance box I can use to try stepped values for the resistor that feeds the 6sc7 and 6sl7. Any more headroom to be gained by increasing the 6l6 screen voltage?

Also, I still have ghost notes like crazy when playing two notes at a time. I have one more 20uf section in my 40/20/20/20 cap can I could bring into play. Any suggestions for adjusting lead dress? Should I be twisting ground and B+ leads together? Tino Z suggests adding a .1uf snubber cap across the output transformer as per the schematic below. Perhaps I'll try that but I'd rather fix things by adjusting lead dress.

[LeftyStrat]

Might try build a Standel 25L15 ...

FYI: http://www.el34world.com/Forum/index.php?topic=14263.0

Amazing build. Will either inspire or make you curl up in the corner and cry.

Man, that cabinet is beautiful. Tubenit goes by a different name on here doesn't he?

[Matt D]

That Standel-inspired build does look amazing!

[da Geezer]

Might try build a Standel 25L15 ...

FYI: http://www.el34world.com/Forum/index.php?topic=14263.0

Amazing build. Will either inspire or make you curl up in the corner and cry.

Man, that cabinet is beautiful. Tubenit goes by a different name on here doesn't he?

10thTx......10th generation Texan, I believe

[LeftyStrat]

FYI: http://www.el34world.com/Forum/index.php?topic=14263.0

Amazing build. Will either inspire or make you curl up in the corner and cry.

Man, that cabinet is beautiful. Tubenit goes by a different name on here doesn't he?

10thTx......10th generation Texan, I believe

Oh, okay, Jeff. I lived in Dallas, Texas for a year. Wonder where he got the wood?

Seriously, that is a beautiful cab. His work is awesome.

[10thTx]

The wood is sapele, flamed maple and (I think?) bookmatched walnut or crotch mahoganey front panel.

I got it all at the Woodcraft store in Charlotte, NC.

Yes, I am a generational Texan. My relatives were cattle ranchers in the hill country around San Saba & Lampasas area in early 1830's.

As a side note, HotBluePlates had access to looking at a true original schematic but is not able to share the information because of a commitment to not share.

With respect, 10thtx