ODS in Progress

[talbany]

My theory on this is this .

100 watt amps will seem louder due to the increased bandwidth propagated by the EXTRA output tubes, this decreases the load on the tubes themselves so you don’t get the anomalies associated with a tube about to clip. This gives the amp more headroom, increased low end, better touch sensitivity, and a clearer cleaner top end, in effect making the amp seem louder since you are hearing a clearer richer sound produced..

Many might argue this statement..I believe it to be true.. A good example of this is the common thread that to me runs through Robben's tone (Here we go again with a Robben example) is he always has that nice sweet chime on the top..Nice and clear.. Classic example of 4 output tubes vers 2..Classic Dumble tone.. Sorry to hijack!!


Tony VVT

[Tubetastic]

Another question for Tony : How do your 4 x 6V6 amps in this style compare to 4 x 6L6? What difference do you notice? Thanks.

[talbany]

For me personally I don't care to much for the 4X6v output section...Many love it..For me it sort of defeats the purpose... The appeal of the 6V's is in the smooth breakup character of the smaller plates... so in this case you want the tube to break (unlike the 6L's in a D-Style)...... Nothing like 6v's going into saturation... SING!!!... ...The 4X6v design really shines when you can crank it get the tubes singing.
As far as a 4X6v in a Dumble style they're pretty cool but lack the low end girth, feel, etc. the ODS is re noun for....





Tony VVT

[Tubetastic]

Thanks, Tony.

[ChrisM]

Got some more work done, and came upon a few "issues".

I want to get this straight is the Ratio pot 100K(B) and the Level is 250K(B)? Do I have the tapers right?

Also I am populating the main eyelet board. Does the presence (390R/1mF) and speaker out not have a chassis ground? They all connect together and I keep thinking they ground to the cathodes but they don't. The layout doesn't show them connecting to the cathodes or making any ground connection to the chassis that I see. O I guess they ground through the sleeve of the speaker out jacks? The schem shows the cathodes connected to the presence circuit though.

From the Master's wiper runs a brown wire. It randomly breaks on the way to the effects loop though. It is soldered on to an eyelet then another wire takes it to the jack. Any idea as to why HAD did this? Just call him nuts...?

Thanks guys!

[dogears]

Careful with this one. Many feel that the 100Kb on both pots is best. I have tried both ways and for me the 100Kb on ratio and level is better. I know Gil felt the same. Every amp is different and don't blindly follow a tweak like this, especially since it is out of the norm.

Got some more work done, and came upon a few "issues".

I want to get this straight is the Ratio pot 100K(B) and the Level is 250K(B)? Do I have the tapers right?


Thanks guys!

[ChrisM]

Careful with this one. Many feel that the 100Kb on both pots is best. I have tried both ways and for me the 100Kb on ratio and level is better. I know Gil felt the same. Every amp is different and don't blindly follow a tweak like this, especially since it is out of the norm.

Got some more work done, and came upon a few "issues".

I want to get this straight is the Ratio pot 100K(B) and the Level is 250K(B)? Do I have the tapers right?


Thanks guys!

Sorry I was looking for what was stock in #124, yet to do any modding.

[Guitarman18]

ChrisM wrote:

Also I am populating the main eyelet board. Does the presence (390R/1mF) and speaker out not have a chassis ground? They all connect together and I keep thinking they ground to the cathodes but they don't. The layout doesn't show them connecting to the cathodes or making any ground connection to the chassis that I see. O I guess they ground through the sleeve of the speaker out jacks? The schem shows the cathodes connected to the presence circuit though.

Presence network most often grounds through the power amp input jack. I also seem to recall a thread that mentioned that HAD also grounded to V2a/b cathode eyelet in a daisy chain to ground on other occasions.

Hope this helps.

Cheers, Paul.

[ChrisM]

Did a bit of work a while back, then went away for a while. Came back yesterday and got a bit more work done today. So far I have done all chassis work. Well actually I need to grind the chassis under all the 1/4" jacks but o well. All hardware fits and there is no problems! Mounted and tightened all the back hardware but not the front yet. Still missing an 18mm 250K(A) pot!!!

Also started work on the PSU and main board eyelet. Still not total complete on either of them. Still have to do more research and figure a few things out. Also wired the heaters, did them in the true HAD ODS style.

O also got a 50W Bassman OT, it has 4R, 8R and 16R taps.


[IMG:640:480]http://img.photobucket.com/albums/v610/ ... aters1.jpg[/img]
[IMG:640:480]http://img.photobucket.com/albums/v610/ ... aters2.jpg[/img]
How do the heaters look? I tried to do them the same as the real deal.

[IMG:640:480]http://img.photobucket.com/albums/v610/ ... /ODSOT.jpg[/img]

[IMG:640:480]http://img.photobucket.com/albums/v610/ ... Eyelet.jpg[/img]
Wire color coding same as real #124. Really like this solid core teflon wire.


How so I look so far?

Thanks guys!

[dogears]

124 had a .01 midcap. Skyline stack... Yours has a .05, no?

[ChrisM]

Ah very good spot, thanks so much.

Yes that cap on the far far right is 50nF, should be 10nF.

[tubedogsmith]

FWIW, I put the heater wire in last so I don't have to solder everything else around it.

[ChrisM]

FWIW, I put the heater wire in last so I don't have to solder everything else around it.

I used to do that as well. I found it always got messier for me though

Can anyone tell me the stock pot values in #124 of the Level and Ratio controls?

[Structo]

250K Ratio

100K Level

That's what my layout for 124 shows.

[ChrisM]

250K Ratio

100K Level

That's what my layout for 124 shows.

Ya that's what the #124 layout in the file section shows. If you compare the schem to layout though they are different. That's where I am having trouble.