New ODS 100W build with pictures...

[heisthl]

voltages are way too low on V2 - that must not be a 12ax7 or it doesn't like the wierd cathode resistor swap.

[ic-racer]

A couple of questions...

How come you so faithfully followed much of 124, but then used different plate/cathose values? You may decide to try the standard 220K>100K network for OD since you used higher plates.

On that subject, how come you swapped the cathode resistors? That is a mistake unless you had some reason to do it.

I am using a stock Ceriatone preamp board. I have all the components to convert the Ceriatone board to #124, but there have been a lot of Ceriatone Overtone posts on Youtube and here that sounded good, so I thought I would keep those Ceriatone values to start with (except the OD trimmer).

My mistake on the naming of the values. I called V1A the first one in the chain, but it is really the second stage of the tube.

You had mentioned in another post about changing V2B to a 4.7 which I may try first.

I had to cannibalize my CTS 100k trimmer to save the CTS 350k trimmer that bludo sent me as it got damaged in shipping. Now that the whole electronics hobby business is 'mail based' getting a 25 cent part is a problem

[ic-racer]

I checked that V2 tube and it faintly shows "12AT7" so I replaced it with a 12AX7.

Voltages (signal path going to the B portion first etc.):

V2A 205v, 1.6v (120k, 1.8k-1.0uf)
V2B 193v, 1.8v (180k, 2.7k-4.7uf)

[JimiB]

mucho mejor!

[dogears]

Ah!! Cool... Should sound MUCH MUCH better. No??

I checked that V2 tube and it faintly shows "12AT7" so I replaced it with a 12AX7.

Voltages (signal path going to the B portion first etc.):

V2A 205v, 1.6v (120k, 1.8k-1.0uf)
V2B 193v, 1.8v (180k, 2.7k-4.7uf)

[ic-racer]

Actually the difference was not as much as I expected. I think the AT7 in there has some tonal possibilities. But to keep on the same page as everyone else I put one of my better RCA 12AX7 in there.

I also put the 4.7uf in place of the 1.0 uf, but more about my experience with that later....

Overall I don't have any complaints with the amps tone. Next I need to figure out which guitars sound best and which speakers sound best. Right now I am using a closed-back Mesa Recto cab with Vintage 30s just because it is set up with the microphone, but I have 5 other possibilities to try:

Open back dual Vintage 30s
Open back quad Alinco 10s
Open back Celestion Modern Lead 70
Open back dual 12" Celestion ?? type (Marshall cab)
Open back 70s Twin cab (Fender branded ?? type)

So here are a couple of tracks just to show the thing really works!

First 4 times through the progression it goes CLEAN, CLEAN & BOOST, OD, OD + BOOST. The OD with no boost sounds a little nasal, but with the same panel settings I could not get all 4 to sound the best at once with that particular guitar.
http://soundclick.com/share?songid=6430994

Here is another one with just OD sounds:
http://soundclick.com/share?songid=6430982

[pedro]

Great clips - really nice expression

I agree that the OD w/o boost sounds a little thin but many players use OD with boost anyway. I'm sure its something that can be overcome with cap tweaking if you want to add a little more bottom/mid to the tone, but I like the OD with Boost very much so maybe dont change it ! - especially on the growly double stops at around 3:10, very dumblish.

I too have 4x12 with V30's closed back and I know others on the forum dont like this setup for the dumble. you will get a very different response from other cabs - as I have when I've borrowed them to try with the amp.

What guitar were you using in the clips ?

anyway, nice one, congrats

Pedro

[Tonegeek]

First 4 times through the progression it goes CLEAN, CLEAN & BOOST, OD, OD + BOOST. The OD with no boost sounds a little nasal, but with the same panel settings I could not get all 4 to sound the best at once with that particular guitar.
http://soundclick.com/share?songid=6430994

Here is another one with just OD sounds:
http://soundclick.com/share?songid=6430982

Great sounds and playing! where did you get your relays and do you have a part number for them? I have been using the ec12nj from Mouser but I cant find sockets for them so I am going to redesign my relay circuit for relays that can be socketed. Yours look like the ticket. thanks

[ic-racer]

What guitar were you using in the clips ?

Those two were done with a Les Paul Custom.

[ic-racer]

Great sounds and playing! where did you get your relays and do you have a part number for them? I have been using the ec12nj from Mouser but I cant find sockets for them so I am going to redesign my relay circuit for relays that can be socketed. Yours look like the ticket. thanks

I got the relays and the boards and sockets from Niki at Ceriatone.

[ic-racer]

I fixed that Popping noise when turning the standby off. In my haste to finish the amp, I had inadvertently soldered the center tap from the OT to a point AFTER the choke. It should be BEFORE the choke. I re-connected it correctly and the loud pop is gone.

[ic-racer]

I have the chassis fitted into the amp cabinet now...more picture to follow.

[ic-racer]

Final pictures.

[ic-racer]

More...

[ic-racer]

duplicate