Low Plate Classic Layout

[talbany]

Whit

Those comments there on the side were taken right off Gil's notes he posted when he and Billy were into the amp.. Yes it is is tube specific however some here believe the sweet spot there can be found between 5-10V higher for FB side..
Hope this helps!!

Tony

[Tonegeek]

Whit

Those comments there on the side were taken right off Gil's notes he posted when he and Billy were into the amp.. Yes it is is tube specific however some here believe the sweet spot there can be found between 5-10V higher for FB side..
Hope this helps!!

Tony

Makes sense. I forgot the most important fact - the tube! No guarantee the triodes are matched or that it would sound the best even if they were.
thanks

[Max]

Whit

Those comments there on the side were taken right off Gil's notes he posted when he and Billy were into the amp.. Yes it is is tube specific however some here believe the sweet spot there can be found between 5-10V higher for FB side..
Hope this helps!!

Tony

Makes sense. I forgot the most important fact - the tube! No guarantee the triodes are matched or that it would sound the best even if they were.
thanks

What Alexander Dumble once recommended concerning this topic I've posted here:

http://ampgarage.com/forum/viewtopic.ph ... 221#134221
http://ampgarage.com/forum/viewtopic.ph ... 247#134247

Cheers,

Max

[Max]

4th generation "classic" ODS 100W clips:

These four video clips are IMO a useful demonstration of some of the tones of the clean and OD channel of this 4th generation "classic” ODS circuit - which Tony documented in the layout he posted in the OP - including demonstrations of the way the "bright" and "deep" switches and the "rock/PB/jazz" switch influence its tone. And they give an impression of the FET tone, too:

http://www.youtube.com/watch?v=34Y3lHpKXWY
http://www.youtube.com/watch?v=SNSAj6AzWGo
http://www.youtube.com/watch?v=-qvMwCte8TE
http://www.youtube.com/watch?v=pGPxrt7d6xk

Cheers,

Max

[dogears]

While I appreciate the effort that went into these clips, IMO, they are a terrible representation of the amps tone. The sound on all of these is not very good. IMHO again. I would not be the least bit interested in this amp if I only went by these clips. Am I the only one to agree?

4th generation "classic" ODS 100W clips:

These four video clips are IMO a useful demonstration of some of the tones of the clean and OD channel of this 4th generation "classic” ODS circuit - which Tony documented in the layout he posted in the OP - including demonstrations of the way the "bright" and "deep" switches and the "rock/PB/jazz" switch influence its tone. And they give an impression of the FET tone, too:

http://www.youtube.com/watch?v=34Y3lHpKXWY
http://www.youtube.com/watch?v=SNSAj6AzWGo
http://www.youtube.com/watch?v=-qvMwCte8TE
http://www.youtube.com/watch?v=pGPxrt7d6xk

Cheers,

Max

[jelle]

That amp is a wonderful ODS.

[Max]

While I appreciate the effort that went into these clips, IMO, they are a terrible representation of the amps tone. The sound on all of these is not very good. IMHO again. I would not be the least bit interested in this amp if I only went by these clips. Am I the only one to agree?

Hi Scott,

Hope you are well!

You often posted here already that you do not like the tone of the 1979 to 1988 "classic” ODS amps that much and that you prefer the one of the late eighties to current skyline ODS amps.

Just one example from another thread: http://ampgarage.com/forum/viewtopic.ph ... 219#120219

the 70s circuits I have tried have paled for me when compared to the 80s grail non HRM Skyline circuit

So perhaps it is not that surprising that you think that these clips are of no use as you have already posted in this thread, too: http://ampgarage.com/forum/viewtopic.ph ... 729#121729 And in this thread some other members have already posted that and why they think different.

However:

If these clips are a useful demonstration of some of the tones of the 1979 to 1988 transition generation and 4th generation "classic" amps or not is in my opinion not that important to find out. Why?

The tone of these 1979 to 1988 "classic" ODS amps is on countless records because many of these have been used by professional session players. And because of this there are IMO more than enough "high quality clips" available, which every one here can use to decide for himself if he likes their tone and if he thinks that the additional information given in these videos is useful as a further impression or not.

All the best and thanks for your perspective,

Max

[dogears]

Hey guys,

Not doubting that the amp is wonderful. Just saying that I don't like the clips. The sound quality is very subpar and for me makes the point of reference moot.

Jelle, you played it. Do these clips sound at all like the amp in person? Be honest.

[Structo]

What is the number of that amp?

[Max]

Larry Carlton with a 4th generation "classic" ODS 100W:

http://ampgarage.com/forum/viewtopic.ph ... 685#137685

Cheers,

Max

[jelle]

Hey guys,

Not doubting that the amp is wonderful. Just saying that I don't like the clips. The sound quality is very subpar and for me makes the point of reference moot.

Jelle, you played it. Do these clips sound at all like the amp in person? Be honest.

I agree that the sound of the clips is not that good. However for the cleans you can get a good idea how this amp processes the information from the guitar. The high end information does not have strong presence in this particular amp, it is sort of filtered away, the mids are just wonderful. The clean sustain is very apparent in the clips. The OD sounds in the clips are indeed very shreddy. And Doug does an outstanding job playing this stuff. When I played the amp it sounded very much like me, but with a really good voice. The touch sensitivity and the voice of this amp was outstanding, as was the feel of the amp. Very versatile amp as I could get a lot of sounds from it, like Max already mentioned being the case for this generation of amps.

Jelle

[dogears]

Agree! That was my point.

I agree that the sound of the clips is not that good. However for the cleans you can get a good idea how this amp processes the information from the guitar. The high end information does not have strong presence in this particular amp, it is sort of filtered away, the mids are just wonderful. The clean sustain is very apparent in the clips. The OD sounds in the clips are indeed very shreddy. And Doug does an outstanding job playing this stuff. When I played the amp it sounded very much like me, but with a really good voice. The touch sensitivity and the voice of this amp was outstanding, as was the feel of the amp. Very versatile amp as I could get a lot of sounds from it, like Max already mentioned being the case for this generation of amps.

Jelle

[crbowman]

Tony,
.....
Dude!
...........
Your work here is GREATLY appreciated!
If you ever get to Austin, I owe you a pint or three.
CB

[talbany]

Tony,
.....
Dude!
...........
Your work here is GREATLY appreciated!
If you ever get to Austin, I owe you a pint or three.
CB

I have 2 rules..

1.. Never turn down
2 Always accept free drinks..

Your on and Thanks for the invite..

Tony

[Structo]

Tony,
In the notes you state the feedback side of the PI is 10v HIGHER than the non-feedback side. My experience with similar designs is the opposite - the DC voltage is lower on the feedback side (but the AC gain is higher). Should I try to adjust my trimmer to go the other way?
thanks,
whit

We seem to be getting conflicting advice about the PI trimmer.

I have in my notes several people that have said it is the non feedback side or input of the PI that is supposed to be 6 volts DC higher.

It makes sense since that is the lower of the two plate resistors unless you are using equal value plate load resistors.

In my amp I use 110K and 120K and the 110K side is the higher voltage.

So in other words, if you use the common 100K / 110K plate resistors, the 100K side should be 6v higher.
The input should be higher.

It gets confusing because some people wire their tubes so that the second triode is first. Thereby Pin 6 is the first plate. Like #124 and most of HAD's amps are.

In looking at the #124 layout the 100K resistor is on Pin 6 the first triode.
It is that side you want a little higher voltage on.

Concerning the notes on the #124 layout, it reads exactly the opposite of what I have been told about balancing the PI voltage.

I have notes from Andy, Funk, Henry and Scott that all say it is the non feedback side or input of the PI that should have the higher plate voltage.