Getting a smoother OD

[ijedouglas]

Phil,

Try set it between 23-26K to ground as a starting point (I checked the schematic and confirmed it's a 100K). The amp must be on with the OD engaged when taking the reading.

Regards

Ian

[jcsifu]

Like others have said I think break in is going to help some as well as trying different speakers as mentioned by others also. Some like the EV and some like me like the celestion 65's. I know someone who used a Wharfedale from a vox ac30 because it took the highs off to his ear. My first amp was the same kit you have, I found that changing the dale plate resistors out with different ones helped the harshness some. The use of the Dumblator and the ability it gives you to turm the amp master up and use the dumblator as a master volume helps for lower volume. The first time I took mine up to gig volume and in a band setting I was surprised by how nice it sounded and felt. Nice job on a first build, this is not an easy first amp to do....and welcome to the forum.

[philbard]

Like others have said I think break in is going to help some as well as trying different speakers as mentioned by others also. Some like the EV and some like me like the celestion 65's. I know someone who used a Wharfedale from a vox ac30 because it took the highs off to his ear. My first amp was the same kit you have, I found that changing the dale plate resistors out with different ones helped the harshness some. The use of the Dumblator and the ability it gives you to turm the amp master up and use the dumblator as a master volume helps for lower volume. The first time I took mine up to gig volume and in a band setting I was surprised by how nice it sounded and felt. Nice job on a first build, this is not an easy first amp to do....and welcome to the forum.

My build is a 50 watt, is the EV a good match for a low power scenario? I understand its rated at 200 w and wonder if it needs to be pushed harder to really sound great.

[ijedouglas]

Highly recommend the 12Ls. Try get an older one if possible. The 200W is max handling, the 50W should be more than enough to drive it. I also really like the EV SRO (Coffee Can) which was the 12Ls Alnico predecessor. The EV have a very flat response and can be a little scary as they reveal EVERYTHING

Regards

Ian

[jcsifu]

Like others have said I think break in is going to help some as well as trying different speakers as mentioned by others also. Some like the EV and some like me like the celestion 65's. I know someone who used a Wharfedale from a vox ac30 because it took the highs off to his ear. My first amp was the same kit you have, I found that changing the dale plate resistors out with different ones helped the harshness some. The use of the Dumblator and the ability it gives you to turm the amp master up and use the dumblator as a master volume helps for lower volume. The first time I took mine up to gig volume and in a band setting I was surprised by how nice it sounded and felt. Nice job on a first build, this is not an easy first amp to do....and welcome to the forum.

My build was a 50 watt, is the EV a good match for a low power scenario? I understand its rated at 200 w and wonder if it needs to be pushed harder to really sound great.

My OTS was a 50 watt too, just a way older one I did back in 2010 I think. The EV is a fine match for a 50, the cones move well even at a lower volume.

The EV have a very flat response and can be a little scary as they reveal EVERYTHING

So very true Ian! I like them in my BM but with my 102 I like the Celestions.

[talbany]

IMO all play a role.

Layout/Lead Dress
Resistor Choice
Treble cap brand
Capacitor Orientation
Tube Selection
Plate voltages
Break in Time

IF the breakup is musical (not harsh) the amp can still be a bit on the bright side like 102 is, and still be smooth regardless of the type of speaker.IMO
Treble bleeders, large snubbers long coax runs and a darker speaker are IMO band aids over a harsh amp..
Getting a non HRM ODS to sound smooth/Musical and still be fairly bright and balanced in OD can be IMO a challenge

Tony

[erwin_ve]

Phil: just to be sure, if this is based on the #102(FM50?) there might be a 68pF on the master volume.
At low master settings this will result in a overly bright amp and a harsh od.
Is this what you have?

Erwin

[ChopSauce]

...its rated at 200 w and wonder if it needs to be pushed harder to really sound great.

As a side note: I've read - and believe - that this should be regarded as a legend. I tend to prefer highly power rated speaker anytime.

I'm happy you invited the others to summarise their experience in one thread, here, which they did. So thank you too!

[10thTx]

I'm gonna offer a suggestion to consider ……………………

IF you have an FX loop, try putting in a equalizer and then work at shaping the treble, mid and bass using the EQ. Doing this has helped me somewhat figure out where the "harshness" is
being dialed in and where it needs to be dialed out. This may give you some hints on how to make the OD smoother?

While it's Dumblish heresy, I've gone to using a James tone stack between the OD gain stages in my Dumble inspired Carolina Overdrive Special. And I'm happy with it. Looking at the Duncan Tone Stack calculator, it's pretty amazing how much the James tone stack can add mids or cut mids.

Just a thought about trying an EQ pedal in the FX loop.

With respect, 10thtx

[philbard]

Phil: just to be sure, if this is based on the #102(FM50?) there might be a 68pF on the master volume.
At low master settings this will result in a overly bright amp and a harsh od.
Is this what you have?

Erwin

Looks like not...

Master.jpg

[scotto]

My Ceriatone from the early days came with a crappy sounding OT. They may be better now, but changing that one out for a Heyboer really smoothed things out.

[philbard]

My Ceriatone from the early days came with a crappy sounding OT. They may be better now, but changing that one out for a Heyboer really smoothed things out.

No way for me to know how big a role the OT plays in my build since this is my first. If I wanted to swap do you know which model Heyboer I would need?

[martin manning]

No way for me to know how big a role the OT plays in my build since this is my first. If I wanted to swap do you know which model Heyboer I would need?

The standard 100W ODS OT is Fender Twin Reverb/Showman, so you want the equivalent to that for a 100W, or a Blackface Bassman equivalent for a 50W. The Heyboer site directs retail customers to buy from Mojo, whose Twin Reverb part number is 775, Blackface Bassman is 774. No one here has heard your amp yet, so we don't know how smooth it is or isn't ;^)

[philbard]

No way for me to know how big a role the OT plays in my build since this is my first. If I wanted to swap do you know which model Heyboer I would need?

The standard ODS OT is Fender Twin Reverb/Showman, so you want the equivalent to that. The Heyboer site directs retail customers to buy from Mojo, whose Twin Reverb part number is 775. No one here has heard your amp yet, so we don't know how smooth it is or isn't ;^)

Yeah, I want to clarify the fact that the clean tones are pretty much exactly where I want them to be. Its the OD channel that feels a bit too sharp. I'm disinclined to think its a component in the overall signal chain rather than something the OD channel, either its design in the #102 model, or perhaps I don't have something quite right. I'm new to building amps and especially to Dumble's so I'm not able to make that call. Nobody had mentioned that my lead dress looks problematic yet, and I'm surfing the forum for treble control posts. It may just be that what I need for my own preferences is an HRM style OD tone circuit, it has been mentioned I can add that and I saw that there is certainly room in the chassis from looking at the Ceriatone gut shots. Thanks for the info on the OT

[jcsifu]

I think it might be important to remember that it is a new build and as others have said, needs to break in. I would give it a minute to do so before trying to change out components. If you change things out before a break in period, you really don't know what the amp's base line is for sound. Especially since you like the clean tone already.

I changed the OT out on my OTS, like I said before it was the earlier one and I agree it wasn't a great OT. And as someone else mentioned, I also noticed a noticeable difference in my tone afterwards.