Interstate 88 Sch File First Attempt So Be Kind

[Ed_Chambley]

Here is my first attempt at Express drawing.  I will get used to it as it is just another program.  I did this from memory (slow day at work) and do not know the Bias Section Values.  I will add them later, but check this and let me know if there is an easier way to make series caps on a schematic. 

Please check let me know if anything is obviously wrong.  My memory ain't what it used to be.

[sluckey]

check this and let me know if there is an easier way to make series caps on a schematic.

Yikes! Those filter caps are not in series. If you have them wired this way in the amp, that explains why your caps keep failing.

[SILVERGUN]

Hey Ed, looks like a nice simple circuit...  

Maybe it's me, but I think I see a problem with the way you have the filter caps drawn out,,,,,but, if you're drawing is correct, and that's the way you have them wired, then that might explain you're cap nightmares

Again,,,I'm no expert,,,and I hate being the guy to point out a flaw,,,but I guess that's why we're here  

I'd be looking for them to look more like this:

EDITED---SLUCKEY BEAT ME TO IT 

[Ed_Chambley]

check this and let me know if there is an easier way to make series caps on a schematic.

Yikes! Those filter caps are not in series. If you have them wired this way in the amp, that explains why your caps keep failing.

I did not know how to draw them.  I have them wired just like Doug explains in the library using 8 pole tagstrips.

[Ed_Chambley]

Hey Ed, looks like a nice simple circuit...  

Maybe it's me, but I think I see a problem with the way you have the filter caps drawn out,,,,,but, if you're drawing is correct, and that's the way you have them wired, then that might explain you're cap nightmares

Again,,,I'm no expert,,,and I hate being the guy to point out a flaw,,,but I guess that's why we're here  

I'd be looking for them to look more like this:

EDITED---SLUCKEY BEAT ME TO IT  

No problem.  I just did not now how to draw them.  They are wired like flashlight batteries only with resistors.  I will fix the schematic.

[tubenit]

I wonder if the Interstate 88 is similar to the Highway 99 schematic and layout posted in the SCH Library in 2007?   

http://www.el34world.com/Forum/index.php?topic=2185.0

With respect, Tubenit

[Ed_Chambley]

I wonder if the Interstate 88 is similar to the Highway 99 schematic and layout posted in the SCH Library in 2007?   

http://www.el34world.com/Forum/index.php?topic=2185.0

With respect, Tubenit

Don't know, But I will check.  This amp as simple as it seems really has a great pallet of tones.  Very responsive to any changes made to the volume or tone.  It is very similar to a Z Route 66, except I need to add the Master to the schematic.  I saw one of yours with the LarMar master I plan to copy.

BTW,  I found out the problem with the caps.  Bad diodes.  Should have checked them when I had the problem with the first cap.  Anyway, it gave me an excuse to make a nice cap board.  Now I am waiting on some 3amp diodes and some matched tubes.  Glad there is no time limit on it.

[Ed_Chambley]

It is like the Highway 99.  That is the same as the DR Z Route 66 with KT66.  Great sounding amp and probably makes more scene than what I have built.  I have solved the cap problems as I had 1N4007 diodes passing AC.  I am building a cap board so it will look better, the tagstrips work well, but do not look nice.

Since I found the bad diodes I am simply going to remake the power section from the diodes through both series caps.  I am not sure about the caps I had in, but they are causing noise and I really do not feel confident about them, however they were working.

Here is a revised schematic.  Please check.  I will have a version 2 as IMO the LarMar master is and should be part of the design.  Can anyone tell me what schematic they have seen the LarMar master in.  It is in one of Tubenit's designs.  I could look through them, but it may take days since Jeff has so many.

[tubenit]

I've never done a PPIMV with fixed bias.  All mine have been cathode biased.

However, Timbo started an excellent thread about fixed bias PPIMV:

http://www.el34world.com/Forum/index.php?topic=15026.0

Note Sluckey's comments in particular.

Ah, found another really good thread about this. Again, look at Sluckey's comments about fixed bias and PPIMV.

http://www.el34world.com/Forum/index.php?topic=14577.0

Another option that you may not want ............ would be to change to cathode biased if you didn't mind some less volume/wattage?  

To "simulate" a kinda sorta quasi fixed bias tone .......... just use a somewhat large cathode cap like 100uf to 220uf.

With respect, Tubenit

[Ed_Chambley]

Here is my attempt.  Please check and let me know if there is a better way to draw the master.

I tried cathode bias in the first amp since the PT did not have a Bias tap.  Then went through the trouble to make dual bias.  Not much difference, but it is what my friend wanted.  I did notice the lower mids were more pronounced and humbuckers were more articulate and the lower notes on the Telecaster were more in line with the Bakersfield tone.

I am not really building a rock amp, but there is not much difference in new country and old rock insofar as overdrive, but it still has to clean up and be loud.

I was told my a few not to build an amp with this much voltage, that is why I am doing it.

Not really worried about the problems I have had so far.  The time and additional cost is well worth the learning experience.  Look, I am even learning to use Express SCH.  I just wish you could scale images in the program.

[sluckey]

You have several mistakes in your PPIMV drawing. Make it look like this...

[Ed_Chambley]

It is the dual pot that messes with me.  On a schematic, when you see 2 pots how do you know if they are dual or not.  I have revised the schematic.  Please check.  I numbered the pot lugs 1 and 3 to show the 2m2 resistor is between the wiper and lug 3.  This is always confusing to me.  What is the "rule" for showing a dual pot?

[sluckey]

There are two common methods that I see frequently. You can annotate the schematic to show it's a dual pot. Or you can draw a dashed line connecting the two wipers to indicate the wipers are mechanically linked together. Or do both. See pic...

Edit... BTW, you can use the shields to connect the bias voltage to the pots.

[Ed_Chambley]

Added.  I think by reworking the filter caps, I will have room to install a loop.  Least that is what I am hoping to achieve.  Please check revised schematic.

[tubenit]

Here is an active on board FX that I like alot. Using something like this, the PPIMV may be somewhat redundant because this works quite well as a master volume, IMO.

I have this very FX in all 3 of my amps and I am very pleased with it.

I have no agenda for you ........ just offering something to consider. 

With respect, Tubenit

[Ed_Chambley]

Here is an active on board FX that I like alot. Using something like this, the PPIMV may be somewhat redundant because this works quite well as a master volume, IMO.

I have this very FX in all 3 of my amps and I am very pleased with it.

I have no agenda for you ........ just offering something to consider.  

With respect, Tubenit

Thank you.  I am relatively easy going and have respect for you ideas.  Keep them coming even if you do have an agenda.  Doesn't bother me.
I do not have chassis space for this mod.  Loads of eddy current flying and I had to really get he lead dress perfect or the noise was sort of bad.  I like an amp that you do not know is on till you hit a chord.  I read where you made one in a separate box.  Would it be possible to do that and simply use a passive loop and run this one through it.  Been wanting to build that ever since I saw it.  I think it would be great to be able to use it on different amps.

I do not have the layout for it.  Can you post it?  Thanks in advance.

[tubenit]

Yes, you can use one in a separate box and insert it in a passive effects loop.

Picture of one, schematic and layout are all on reply #5 of this thread:

http://www.el34world.com/Forum/index.php?topic=10624.0

With respect, Tubenit

[Ed_Chambley]

Yes, you can use one in a separate box and insert it in a passive effects loop.

Picture of one, schematic and layout are all on reply #5 of this thread:

http://www.el34world.com/Forum/index.php?topic=10624.0

With respect, Tubenit

Thanks, you are a fine feller.  I don't care what Jim says.