Blues Deluxe to ODS build

[Amwatts]

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Hi all,
I've just completed my Retro Custom conversion on a 1st edition Blues Deluxe Chassis
I used the latest Schematic Rev F . It's turned out great with the Normal Channel, very clean and the boost really sounds great . But I find the Overdrive is a little fizzy , I've heard a few demos of the mod on line and the OD channel isn't as raspy as mine , Comparing it to real Dumble demos it's way different.
I've spent hours tweaking the internal pots but am yet to find and OD setting that doesn't have that raspy fizz , unless I have the OD Gain pot way down to almost off and the OD volume up to 9-10 ,
Is this how it's supposed to sound ?

I used Mallory 150's instead of the Orange drops , and it's through a British made V30

Any thoughts
Cheers Watto

[Amwatts]

More Pictures during the build process

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[bepone]

But I find the Overdrive is a little fizzy , I've heard a few demos of the mod on line and the OD channel isn't as raspy as mine , Comparing it to real Dumble demos it's way different.
I've spent hours tweaking the internal pots but am yet to find and OD setting that doesn't have that raspy fizz , unless I have the OD Gain pot way down to almost off and the OD volume up to 9-10 ,
Is this how it's supposed to sound ?

i'm afraid this is because of this pcb..layout is all but Dumble.. pls write to this pcb manufacturer that you have this problem, and ask him if he really made ODS sound from it, clips

[martin manning]

This PCB has produced successful conversions in the past. Socket wiring around V1 and V2 is critical to preventing parasitic oscillations, and I see you have some long leads running up in the air. Somewhere there is a thread that dealt with this, but I would run the leads more like the Dumble layout, close to the chassis surface, and preserve the order of the triodes on the chassis wrt signal flow, right to left.

[Amwatts]

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This PCB has produced successful conversions in the past. Socket wiring around V1 and V2 is critical to preventing parasitic oscillations, and I see you have some long leads running up in the air. Somewhere there is a thread that dealt with this, but I would run the leads more like the Dumble layout, close to the chassis surface, and preserve the order of the triodes on the chassis wrt signal flow, right to left.

I did move the OD Volume position, I'll move it back and follow it directly , unfortunately the tube sockets aren't directly under the PCB positions , This means longer wires . The amp is quiet for RF hum, but I think I'll play with the lead dress a bit ...

[Amwatts]

But I find the Overdrive is a little fizzy , I've heard a few demos of the mod on line and the OD channel isn't as raspy as mine , Comparing it to real Dumble demos it's way different.
I've spent hours tweaking the internal pots but am yet to find and OD setting that doesn't have that raspy fizz , unless I have the OD Gain pot way down to almost off and the OD volume up to 9-10 ,
Is this how it's supposed to sound ?

i'm afraid this is because of this pcb..layout is all but Dumble.. pls write to this pcb manufacturer that you have this problem, and ask him if he really made ODS sound from it, clips

There's been many successful builds with this PCB, The designers are both members here and are very active in helping with problems that may occur . I did differ slightly from the build suggestions , so I'm hoping it's just an oscillation from the lead dress ...

[bepone]

i'm not sure that this pcb will ever work, no any dumble layout there, this cannot work like dumble , and also with pcb like that there is low posibility for good overdrive.
all those are problems of the designer and he need to provide answers

[martin manning]

Somewhere there is a thread that dealt with this...

See starting here: https://ampgarage.com/forum/viewtopic.p ... 77#p405777

[Amwatts]

Somewhere there is a thread that dealt with this...

See starting here: https://ampgarage.com/forum/viewtopic.p ... 77#p405777

Thankyou .... let the trouble shooting begin ... I'll report back very soon

Question . Is it possible to swap out V2 for a lower gain tube for maybe a 5751 or 12AT7 or does that change the dynamics and current draw too much ? I'm curious as to what that would do ... of course this is down the track a bit once I get the OD channel in check , My thinking is ... Dumble fine tuned each amp for the player so I'm thinking of all possibilities

[martin manning]

I'd get it working with 12AX7's to preserve the original character as much as possible. You can certainly try tube swaps later to see what that does.

[xtian]

I have built a few of these using Lou's board with good OD results. For V1 and V2 especially, remember that the three wires to each triode (control grid, cathode, plate) can be bundled together, but keep these wires separate from the second triode's set of wires.

[pompeiisneaks]

Exactly, that was my build where I was having the oscillation, it had nothing to do with the pcb and everything to do with layout of the wires to the triodes. once I swapped which half of the triode got what leads, the oscillation poofed and went away like a good gremlin.

These PCB's are great, no matter what some people may want to say about them.

~Phil

[Amwatts]

Progress today.
Put all the pots in the sequential order as per the Layout , this removed a fair bit of wire , big improvement , But the OD is still very preamp fizzy, not a fatter output tube style drive , best way to describe it Neil Young OTT fuzz , I'm use to the tweed edge of breakup and plexi kind of breakup... Only just delved into the Dumble world ...

tweaked the trim pots quite a bit , found some cool sounds .... I'm thinking the cheap old Blues Deluxe OT need to be replaced ... I have a Merc Mag Tweed Pro 8 ohm tran spare , Might throw that in

[bepone]

fizz fuzz means that some wire is close to the other wire which should be normally separated

[bepone]

then again if the pcb is fixed, how you can find them and separate them?