2nd Gen hybrid

[erwin_ve]

Great Franco!
I'll see if I can respond to your questions regarding the built in Dlator this week.
Meanwhile you could make a seperate build topic of your amp?
This would make it a little easier to respond to specific questions/remarks as your build is different.

Erwin

[jazzbass]

Great Franco!
I'll see if I can respond to your questions regarding the built in Dlator this week.
Meanwhile you could make a seperate build topic of your amp?
This would make it a little easier to respond to specific questions/remarks as your build is different.

Erwin

Hi Erwin,

I really think I will make an external dumblator unit so that I can use it with multiple amps.
For now the work is going smoothly, I thought it was more difficult to use a non-specific motherboard for a 2nd Gen.
I decided to make a "traditional" PS board instead of the precision power board because it is easier to make and, as you say, "traditional versus precision power supply is not that different in sound"

Thank you
Franco

[jazzbass]

Hi Erwin,

I am attaching the first photos taken of the new build, I am following your directions for the 2nd Gen Hybrid on your 4 hole chassis.

I have decided (finally) that I will install a Kit Dumbleator bought from Tubetown, it seems to me the simplest solution. Can you give me an opinion ?.

I am undecided whether to build a 50Watt or a 100Watt, which of the two versions do you prefer?

A hug
Franco

[Synchu]

No Erwin here - but the 100W.

Niki

[fred.violleau]

Agreed with synchu, 100W is not that much louder, but apparently brings another dimension in the sound a 50watts does not have.

You may still add the half power switch if you think you need less power.

Fred

[erwin_ve]

Jazzbass: 100w has a punchier low end, I prefer that.
You don't need a dlator kit.
It can be done with terminal strips around v3 and the PS filter supply with extra nodes.

[jazzbass]

Thanks Synchu, fred.violleau, Erwin,

I see that you all agree, okay, go for the 100 Watt.
Dear Eerwn, I remember seeing the Dlator built on a terminal strip in another discussion but I don't remember where I saw it, you who have more memory than me please show me where to find it.
Thanks, a hug

Franco

[jazzbass]

Hi Erwin,

after having set up the motherboard, mounted the potentiometers the first doubts arise .... I'm following the layout of Jason Borders with the revision of 11/04/2010 and from the comments read on "2nd Gen hybrid" it seems that there are some errors.
I don't know if they have been corrected but I have taken note of all the variations discussed and have a few questions:
-I can't find the resistors you refer to "but I have either a 1.8 or 3.3k hanging off the bass pot and a few other changes as well".
-Is the wiring of the Jazz / rock switch correct?
-in the layout the 6L6 grid resistors are 2k2 and you wrote that you changed them to 2K, is that correct?
Thank you for your attention and I ask you to please tell me which layout you followed or if you have inserted one on TAG.
Continuing with the construction I will certainly have other questions, have patience ... I hope I am not a "pain in the ass"

Thanks

Franco

[erwin_ve]

Hi Erwin,

after having set up the motherboard, mounted the potentiometers the first doubts arise .... I'm following the layout of Jason Borders with the revision of 11/04/2010 and from the comments read on "2nd Gen hybrid" it seems that there are some errors.
I don't know if they have been corrected but I have taken note of all the variations discussed and have a few questions:
-I can't find the resistors you refer to "but I have either a 1.8 or 3.3k hanging off the bass pot and a few other changes as well".
-Is the wiring of the Jazz / rock switch correct?
-in the layout the 6L6 grid resistors are 2k2 and you wrote that you changed them to 2K, is that correct?
Thank you for your attention and I ask you to please tell me which layout you followed or if you have inserted one on TAG.
Continuing with the construction I will certainly have other questions, have patience ... I hope I am not a "pain in the ass"

Thanks

Franco

Hi Franco,

I used the same layout as you have. There are indeed a few errors, since I dont have the original file I cant improve that layout without putting a large amount of hrs in.

-The basspot lug 3 is missing a resistor to ground; I used a 10k like in a #40 2nd gen ( https://ampgarage.com/forum/download/fi ... &mode=view )

-The wires coming from the PAB board going to the center of the Rock/Jazz switch are reversed, so you need the wire that is on the center left--->> wireing it to the center right and vice versa.

-6L6GC grid resistors in my amp are 2K because thats what I had available at that time. Either 2K and 2K2 should be fine.

No worries on the PITA thing. I will let you know when crossing a line

Have a good weekend!

Erwin

[jazzbass]

Hi Talbany, hi Erwin,

"talbany wrote: ↑ Sat Mar 18, 2017 7:32 pm

Erwin
The build looks great !!
A few points of interest on this design I ended up tweaking on mine

1 ..The 1m bypass resistor on the OD network I lowered to 470k (Kittyhawk) .. This struck a good balance of gain for me at the input volume setting I preferred as well as overall volume I would generally run the amp ..
"DO YOU MEAN THE RESISTANCE THAT IN THE LAYOUT OF JASON BORDERS -2nd gen 100W Hybrid- goes to the pot OD MASTER?"

2 ... I just used the single .002 across the bass pot ..
"BASS POT 2/3?"

4..I also tweaked the resistor to ground on V2b to keep things tight on the way out (I think 150k was what I used).
"SORRY BUT I DON'T SEE RESISTORS GOING TO GROUND IN V2b, IT'S CERTAINLY A PROBLEM IN MY SIGHT ...."

I actually prefer this OD circuit for Strats over the later 3rd generation amps..IMO the absence of the OD vol control plays a big role in why it sounds so good (big & fat dynamic) with single coils..YMMV
"SO THE POT OD MASTER MUST BE ELIMINATED AND CONNECTED THE 1M RESISTANCE TO THE N.O. CONTACT OF THE RELAY CLEAN / OD? OR THE DIFFERENCE IN TERMS OF LOSS OF SOUND QUALITY IS NEGLIGABLE IF I LEAVE THE POTENTIOMETER?"

I know it's an old discussion but I started building a 2nd Gen and, after your observations, I got bogged down .....

Thanks
Franco

[erwin_ve]

Franco:
1. The Od entrance resistor: 1M on the layout, can you spot it?
2. Check the basspot on #124: it has a cap across lug 1 and 3, that's the position Tony is referring to.
3. The v2b cap is going to a 1M resistor, from that junction there is also a resistor going to the junction of the cathode bypass caps negative side=ground!

4.the 2nd gen hybrid has separate masters. From a technical point of view there is no difference if the Od out is seeing either 1M pot.
That is a completely different from the wiring of #124 or #102. Those Od out go to a 100k or 250k pot and then go to the 1M pot.

[jazzbass]

Hi Erwin,

1) in the mother board I see a 1M resistor that goes to a 180K resistor and to ground and the .01uf coupling capacitor, then goes to the 1M OD Master pot, is that correct?
2) OK
3) so the resistance to ground should be 150K instead of 180K?
I understand what you mean by saying that the function of the OD master pot is different from that of other Dumble projects.
Thanks, now I can go on without getting anxious.

A hug, Franco

[erwin_ve]

Hi Erwin,

1) in the mother board I see a 1M resistor that goes to a 180K resistor and to ground and the .01uf coupling capacitor, then goes to the 1M OD Master pot, is that correct?
2) OK
3) so the resistance to ground should be 150K instead of 180K?
I understand what you mean by saying that the function of the OD master pot is different from that of other Dumble projects.
Thanks, now I can go on without getting anxious.

A hug, Franco

1.No, from the relay to the entrance of the od circuit.

3. That is a option, but I advise you to build as the 2nd gen hybrid layout. Later you can put some resistors parallel on those spots to see if you like the lower values.

[jazzbass]

Hi Erwin,

1) the only other resistance in the OD circuit in the mega range connected to the OD relay that I can see is the one that goes to pin 7 of the 12AX7, before the 56k grid resistor, it is 1.2 mega but, if I'm not mistaken, you didn't change it because the sound obtained with the change was too fuzz and therefore ... there is no problem.
Now I have to build the power supply board and the JB layout is very generic, I miss the voltage and / or trace indication on the back of the board that maybe I can find in the TAG discussion or maybe it's a standard PS board.

thanks, Franco

[talbany]

Hi Erwin,

1) the only other resistance in the OD circuit in the mega range connected to the OD relay that I can see is the one that goes to pin 7 of the 12AX7, before the 56k grid resistor, it is 1.2 mega but, if I'm not mistaken, you didn't change it because the sound obtained with the change was too fuzz and therefore ... there is no problem.
Now I have to build the power supply board and the JB layout is very generic, I miss the voltage and / or trace indication on the back of the board that maybe I can find in the TAG discussion or maybe it's a standard PS board.

thanks, Franco

Franco
Just to clarify for you!
1.The .002 cap goes across the bass pot just like the later Skyliners (124)
2.On V2B output coupler you have a 1M in series feeding the relay and a 180K to Gnd..I lowered the 180K resistor
3 On the OD entrance network I lowered the value of the 1.2 M to 470K..Depending on the volume you normally use the amp depends on the value you use. You can also use 680K and 1M, if I could run the amp at a higher volume. IMO Dumble voiced this amp to be played loud
.

I also used Carbon comp resistors in that network that helped keep the OD smooth, That along with the lower 180/185V onV1 also helped with the fuzzy sound. If you just change the 1.2 M to a lower value the amp does get a little fuzzy given those amp have a raw sounding O.D.. By dropping the value of the 180K also helped with the fuzzy sound.


The tweaks that I did were done only to compensate for the lower volumes I use. If I could play the amp as loud as I wanted I wouldn't touch a thing on that amp it's perfect as is so if you play loud then i wouldn't worry about changing both 1.2M and 180K resistors

Tony