My New Early Model PL400 w/ 4 Fin Heat Sink

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
56,699
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#21
Yup...a 400 is plenty for some (satisfied here)....maybe if I were younger I'd go for a 700. Too much time left on Lee's lifetime warranty to give up my 400 though. The 400 has kept me smiling for almost three years now.

Let's hope I live long enough for you to collect on that warranty...
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
56,699
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#22
I still have a hard time visualizing a 17 watt single ended, triple triode, double pentode tuber as being audio bliss.....
 

jbeckva

Admin/Server Dude
Staff member
Joined
Jun 11, 2010
Messages
6,548
Location
Powhatan, Virginia, United States
Tagline
Errm... Ey Vatos!!!!
#28
LOL no doubt. Sorry "toobers", but after working on AN/ARN-52 Tacan's chock full of tubes and becoming an alcoholic as a result... hehe. (Perry will get this.. I think he was clubbing seals while I went to DG aka the "rock")
 

WOPL Sniffer

Veteran and General Yakker
Joined
Aug 10, 2015
Messages
4,052
Location
Arizona
Tagline
Screw it
#29
Haaa...... You thought you were staying in San Diego Garcia (a Mexican suburb of San Diego).... Cocaine is one hell of a drug eh?

You talk about clubbing seals like it's a bad thing (I was clubbing penguins in New Zealand bro).....
 

Gepetto

Administrator
Staff member
Joined
May 15, 2011
Messages
7,466
Location
Sterling, MA
Tagline
Old 'Arn Enthusiast
#31
We currently do not have the PL400 faceplates but will sometime in 2019. Working other priorities first but eventually we will have those.

We have the cap kits for the 4 fin amps. It is a single cap per rail (not the stacked cap) at 12KuF/100V that mount with the band clamps, We have the 50A bridge and the snubber caps. That 200V bridge is not a high enough voltage rating, need at least 400V for 120VAC in a PL amp. The current rating is fine but the Vrr is not.
 

VSAT88

Chief Journeyman
Joined
Sep 7, 2017
Messages
594
Location
Phenix City Alabama
Tagline
Like my BlueTooth ?
#32
Wanna read ? If you have time you could look at how I screwed mine up and just at the brink of insanity the guys here pulled me out. I could give you a few ideas and pictures of what I was told to do and it may well be helpful. Be quite careful with the bias transistor leads if they are mounted to the heat sink back panel on your amp. There are some diffrences between that 4 fin and my 8 fin and not just the amount of fins ...DC protect is a must unless you are going to put that am on a set of speakers that you care not a shit for. I used my stock main board but repopulated it with fresh caps and the double diodes . I changed out the main filters with White Oak. I am very happy with the result. You can always build another amp, a WOPL and use this one on a second system. You can never have enough amps, right ! The guys here are very helpful. You are in the right place to fix er up nice. Let me know if I can be of help.
 

punchback

Journeyman
Joined
Jan 8, 2019
Messages
107
#34
VSAT88 I finished reading about your trials and tribulations on getting your 400 running. I see where you say to be careful of the bias transistors. Hard to see the problem when it's broken off and appears that it's still connected.

Regarding my 400... I'm looking to put a Mouser order together and have a question about the C6 Diode Mod. I have a service manual from HiFi Engine. It doesn't seem to show my PCB parts outline. I believe the 100uF 10V parts indicated are the C6's for the left and right channel. Just looking for a little confirmation. Assuming I've identified the correct cap, what kind of replacement cap should this be audio, low leakage, general etc.? If it should be a low leakage or audio there's not much available in a axial configuration. Could I use a radial and just spread the leads out assuming they'll reach? Does that cause any problems with noise? On the diodes themselves, should be be configured as A or B as shown in the attachment or maybe some other way?

As always thanks for any help.

Alan

DSC_0232.JPG DSC_0233.JPG C6 Diode Mod.jpg
 

laatsch55

Administrator,
Staff member
Joined
Jan 14, 2011
Messages
56,699
Location
Gillette, Wyo.
Tagline
Halfbiass...Electron Herder and Backass Woof
#35
Configuration A. Yep, just spread the leads. I do that a lot on the 3300's to replace axials and have had no problems with it. Audio grade only, Nichicon "Muse" if you can get em.
 

VSAT88

Chief Journeyman
Joined
Sep 7, 2017
Messages
594
Location
Phenix City Alabama
Tagline
Like my BlueTooth ?
#40
Thanks Lee. Punchback what Lee said ! Your mainboard looks more like my PL 700 than my PL 400. My 700 is an early one and your 400 must have been built not too long after my 700. It goes without saying that I measured all the resistors on my board to make sure I was good there. The resistors on the back plane too. There were some out of spec on the back plane. I expected that so they were replaced as well. Hope you ordered 100V + Main Filters and a new BR.
 
Last edited:
Top