New here and new to phase linear

[Northwinds]

The Aerosmith 400 has the same driver board Lee[/QUOT

Forgive me for my ignorance on these but... Whats an Areosmith board?? Only thing I know about Aerosmith is they were a great band.

The amp was part of the backline of amps that Aerosmith used to tour with that Lee bought from a sound company up near Boston and I picked up with a U-Haul. There was only one 400, the rest were 700B's and 700 series I's

 

[roccus]

The amp was part of the backline of amps that Aerosmith used to tour with that Lee bought from a sound company up near Boston and I picked up with a U-Haul. There was only one 400, the rest were 700B's and 700 series I's

Wow thanks for this info... is there anyway to figure out if this was in fact built for Aerosmith?? If it turns out it was it may be best just to rebuild it to keep it original as it would be a piece of rock history. Would then need to buy that 700 to play with the do mods on.

 

[OneTonScoutII]

As said below, you'll trash most of those innards anyway. The biggest difference (other than the fins) is how the power supply caps. and bridge rectifier are mounted. The caps are mounted with with those clamps that hold them to the side of the case instead of the strap that holds them to the aluminum cap that fits over the top of the transformer. White Oak should be able to steer you to the proper caps since their "basic" 400 cap upgrade won't mount with those side mounted clamps. Not a huge deal as long as those caps are available. Probably going to boil down to a non-issue.

I've got a 4 fin and an 8 fin that both need upgrades and I figure I'll start on the 4 fin as a learning experience. Then I can move on to the 8 fin and give that 4 fin to my brother. Then it's the 700B!

Welcome to the mad house.... you'll love it here!!!

I thought if it had Honeywell gauges then the PS caps mount to the chassis.
And if Dixon meters then they mount to the transformer.

I have 2, 4-fin 400's and both have the Dixon meters and both have PS caps that mount to the transformer.

 

[roccus]

This is a pic of the transformer Ser. #342-071

 

[Northwinds]

The Aerosmith 400 also has Dixon meters and the shorter but fatter silver PS caps

 

[OneTonScoutII]

White Oak does not have those caps for this one... I see others on ebay have some that will work so no not an issue. As far as the original mounting clamps go if they are either to big or to small I could always modify them or just make new ones... I'm a fabricator

WhiteOak does offer them, you just need to let him know that you have a early 400 that has the caps that mount to the chassis. I believe its listed on the price sheet as a special option in the capacitor list.
Or like you said you can do it yourself

 

[roccus]

The Aerosmith 400 also has Dixon meters and the shorter but fatter silver PS caps

So this may not be an Aerosmith amp?? Darn I thought maybe I may have turned a mistake into something great. Here are some more pics of it....

 

[Northwinds]

So this may not be an Aerosmith amp?? Darn I thought maybe I may have turned a mistake into something great. Here are some more pics of it...

An Aerosmith amp simply implies it was verified owned by the band and used for touring, yours is most definitely not one LOL. Yours is any early version and so is the Aerosmith. When Dan posts up the images here of it (I lent it to him to check out) you will immediately see they look pretty much identic except from the Hanley Sound mods for ease of use racked. The Dixon meters in the Aerosmith 400 have a bunch of lights that look like fuses. I will see if I have any images of it stored in the computer

EDIT: Several of us here also own amps used during the Dio era of Black Sabbath, I own "Sabbitha"

 

[Gepetto]

I know Ed will want to look at that board . I've never seen a 400 board with 6 pots on it .......that's a first.

Hi Lee
It is the early PL0171 board, 3 point mount and 3 pots per channel. I am sure you have worked on one of these long ago in a PL700.

 

[Gepetto]

It appears on that driver board that one could adjust bias and DC offset, just like the first generation PL 0171 boards used in the early 700's. Are there any numbers on that board??

Bias, input offset, output offset...

 

[Gepetto]

So this may not be an Aerosmith amp?? Darn I thought maybe I may have turned a mistake into something great. Here are some more pics of it....

View attachment 25745 View attachment 25746 View attachment 25747 View attachment 25748 View attachment 25749 View attachment 25750

If you had an Aerosmith amp, you would know it because it would be beat to hell from the roadies. The only difference between an Aerosmith amp and any other PL amp is that any other PL amp looks much better

 

[roccus]

If you had an Aerosmith amp, you would know it because it would be beat to hell from the roadies. The only difference between an Aerosmith amp and any other PL amp is that any other PL amp looks much better

And of course the history or belonging to a wold known band.... is there anything to the serial number that dates these??

 

[Gepetto]

And of course the history or belonging to a wold known band.... is there anything to the serial number that dates these??

They were owned by the sound reinforcement company that supported Aerosmith (Terry Hanley Audio), not Aerosmith.

Your amp was built in March 1972 and was the 71st they made that month.

 

[laatsch55]

Hi Lee
It is the early PL0171 board, 3 point mount and 3 pots per channel. I am sure you have worked on one of these long ago in a PL700.

I never saw a PL0171 in a 400, only the early PL400C's, lots of PL0171's in 700's, yes.....

 

[grapplesaw]

I never saw a PL0171 in a 400, only the early PL400C's, lots of PL0171's in 700's, yes.....

Here is a pl0171 from my 700
it is a bit different than this one.

 

[roccus]

Here is a pl0171 from my 700
it is a bit different than this one.

Orientation a bit different but I see 4 trip posts there.... I wonder what the deal is with the rheostat on the one I have is?

 

[laatsch55]

Someones kludged attempt to replace the bias adjustment potentiometer....

 

[roccus]

Well much has happened since I started on my phase linear journey it started when I got a real nice clean working all stock 4 fin pl400 series 1 my plan was to do a WOPL upgrade on it. A day or so after I bought a black face plate for it and an 8 fin chassis from a member here. After a few days I was liking the amp but the amp just does not have enough head room when you crank it up and started thinking I might be better off to put my time and money into a 700b also I was thinking it would be a shame to cannibalize this nice 4 fin 400 to build a 6 fin 400. But then I also felt I committed my self to the 400 with what I had into it already. I'm not sure how much I will gain on head room doing the 400 up as a WOPL amp but I'm thinking the power cap upgrade alone has to help that out quite a bit then add to that all the other WOPL maybe enough to make me happy with the performance of the amp.

So what I have done and decided is to go ahead with the 400 build using the 8 fin chassis. I have solved the problem of hating to cannibalize the nice 400 by buying another working stock 400 series one that looks like it has nice meters and all. The cost of the 2 400 amps combined is still cheaper than 1 decent stock 700b . If when I finish the WOPL 400 if I am still not satisfied then I could sell both amps and have a real good start for money needed to do a 700b. When everything I have bought gets here I will be putting an order into Joe for all his parts, nav for wiring and then mouser, I will also do the speaker protection circuit on it as well to do it right.

 

[laatsch55]

Output power is a result of amp topology and rail voltage. We get a little bump from going full comp on the 400's but you will generally be within 10% of the original power output.

With the residual noise levels between the 400's and 700's so close there really is no advantage to a 400 anymore.....

 

[roccus]

Did you mean no advantage to the 700??

Output power is a result of amp topology and rail voltage. We get a little bump from going full comp on the 400's but you will generally be within 10% of the original power output.

With the residual noise levels between the 400's and 700's so close there really is no advantage to a 400 anymore.....