Hello! Newbie from Edmonds Washington

ALLENWERK

New Around These Parts
Joined
Oct 10, 2019
Messages
12
#1
Hi everyone,

Sounds like this is the place to be! (lame pun)

I am hoping to learn from and humbly participate with this extremely knowledgeable group. I am very new to vintage audio equipment and have a lot of questions! I recently acquired the following family heirlooms:

Phase Linear 700b and 4000 with wood cases, JBL 4320 studio monitors - The story goes these were supposedly in a bar/venue in North Seattle and were used during an early Aerosmith performance, from which they were booted out of o_O.

So far, I've had the JBL woofers re-foamed at Hawthorne Stereo in Seattle, as well as general servicing/cleaning of the 700b and 4000. Everything seems to be working, except one channel of the amp's output is less than the other side and there is a slight crackling sound when adjusting volume and the meter movement is minute. I don't own any test equipment (yet), although I do own a soldering station and some hand tools. I lack the confidence to attempt my own repairs on this amp, it is very dear to me and would hate to cause permanent damage due to my lack of skills/knowledge. I am seriously considering the White Oak upgrades and would like to know how and who to contact regarding having this done. Is there anyone in the Greater Seattle area?

If not going the full White Oak route, can someone suggest a "basic" restoration parts list/kit to bring it to its former glory? I am of course very curious of the cost difference between the two routes, versus what is gained for a novice audio addict like myself.

I would like to learn more about doing my own repairs and upgrades, can someone suggest a list of entry level test equipment/tools to get me started?

Also, acquired some Bose 901 series VI with original eq and a Marantz 2270 that needs a full resto.

Thanks everyone and Happy Holidays! ;)

-Greg
 

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stetter

Journeyman
Joined
Dec 1, 2018
Messages
190
Location
Tower, MN
#2
welcome to the forum, Perry you need to pipe in now about ( Everything seems to be working, except one channel of the amp's output is less than the other side and there is a slight crackling sound when adjusting volume and the meter movement is minute ) He needs to save those JBLs before it is toooo late!
 

mlucitt

Veteran and General Yakker
Joined
Jun 24, 2011
Messages
2,501
Location
Jacksonville, FL
#3
Echoing stetter above, disconnect those JBLs from that PL700B and DO NOT connect them up until you have speaker protection installed. It is cheap insurance but that PL700B will smoke one or both of your sweet speakers before you can say OUCH!
 

ALLENWERK

New Around These Parts
Joined
Oct 10, 2019
Messages
12
#5
Echoing stetter above, disconnect those JBLs from that PL700B and DO NOT connect them up until you have speaker protection installed. It is cheap insurance but that PL700B will smoke one or both of your sweet speakers before you can say OUCH!
Yikes! Okay, everything is disconnected for now. Thanks for the save :cool:
 

George S.

Chief Journeyman
Joined
Feb 18, 2020
Messages
694
#6
Yikes! Okay, everything is disconnected for now. Thanks for the save :cool:
The PL amp was most probably never upgraded with a speaker protection relay. If the amp is faulty it can send DC current to your speakers and ruin them. All that equipment needs checked out and serviced before being used on your very nice speakers.
 

ALLENWERK

New Around These Parts
Joined
Oct 10, 2019
Messages
12
#7
The PL amp was most probably never upgraded with a speaker protection relay. If the amp is faulty it can send DC current to your speakers and ruin them. All that equipment needs checked out and serviced before being used on your very nice speakers.
Thank you!

So, how can I determine on my own if any DC current damage has occurred and ruined anything already? Will there be any obvious indicators or will I need to have a professional perform tests to the drivers and crossovers etc.?
 

George S.

Chief Journeyman
Joined
Feb 18, 2020
Messages
694
#8
Hi everyone,

Sounds like this is the place to be! (lame pun)

I am hoping to learn from and humbly participate with this extremely knowledgeable group. I am very new to vintage audio equipment and have a lot of questions! I recently acquired the following family heirlooms:

Phase Linear 700b and 4000 with wood cases, JBL 4320 studio monitors - The story goes these were supposedly in a bar/venue in North Seattle and were used during an early Aerosmith performance, from which they were booted out of o_O.

So far, I've had the JBL woofers re-foamed at Hawthorne Stereo in Seattle, as well as general servicing/cleaning of the 700b and 4000. Everything seems to be working, except one channel of the amp's output is less than the other side and there is a slight crackling sound when adjusting volume and the meter movement is minute. I don't own any test equipment (yet), although I do own a soldering station and some hand tools. I lack the confidence to attempt my own repairs on this amp, it is very dear to me and would hate to cause permanent damage due to my lack of skills/knowledge. I am seriously considering the White Oak upgrades and would like to know how and who to contact regarding having this done. Is there anyone in the Greater Seattle area?

If not going the full White Oak route, can someone suggest a "basic" restoration parts list/kit to bring it to its former glory? I am of course very curious of the cost difference between the two routes, versus what is gained for a novice audio addict like myself.

I would like to learn more about doing my own repairs and upgrades, can someone suggest a list of entry level test equipment/tools to get me started?

Also, acquired some Bose 901 series VI with original eq and a Marantz 2270 that needs a full resto.

Thanks everyone and Happy Holidays! ;)

-Greg
Just start reading the threads, looking at the photos, you can learn a lot. There are plenty of threads about rebuilding these amps. I spent about 3 months reading and studying photos before I built two WhiteOakPhaseLinear WOPL amps. If you want a builder to do it for you, they are here and can do it. There are threads and posts about costs. Spend some time reading, just don't plug that equipment in until you learn more about it. Very nice equipment, but it's old, has issues that can be fixed.
 

mlucitt

Veteran and General Yakker
Joined
Jun 24, 2011
Messages
2,501
Location
Jacksonville, FL
#9
Thank you!

So, how can I determine on my own if any DC current damage has occurred and ruined anything already? Will there be any obvious indicators or will I need to have a professional perform tests to the drivers and crossovers etc.?
When the PL700B 'latches up' and sends 100-200VDC to the speakers, the woofers immediately fry, and smoke (and sometimes a flame) results. You would instantly know by connecting another amp to the speakers and hearing that they make no sound. In some cases the crossover will block the DC voltage and take the hit instead of the tweeter. You don't need someone to tell you your speakers are burnt, it is pretty obvious. Yours are likely fine.
By the way, we love talking about speaker carnage here. It is real, but we have solved the problem that the engineers at Phase Linear could not fix. We are fortunate to be in the presence of a talented engineer who runs White Oak Audio. Thanks to Joe, we have access to state of the art replacement parts that make the Phase Linear 400 and 700 amps true reliable powerhouses.
The White Oak Audio Rev E6 or Rev G1 Control Boards will prevent your PL700B from blowing up your most excellent JBLs, available here:
http://www.whiteoakaudio.com/estore.aspx
The DC Protect Relay Board will give you a speaker turn on delay and also prevent any DC from getting past the speaker binding post terminals, here:
http://www.wattsabundant.com/
Welcome to the WOPL club!
 

George S.

Chief Journeyman
Joined
Feb 18, 2020
Messages
694
#10
At the very least get the DCP installed in the 700B by yourself or Hawthorne Audio. The 4000 could be the issue of low output on one channel, as these preamps suffer from bad solder joints and connections between the multiple boards inside. What did Hawthorne Audio say? Try swapping the interconnects around to determine where the problem is. Just don't use those beautiful JBLs until the issues are fixed. Maybe pickup some cheap speakers at Goodwill. If it was me, I'd sell the other equipment to finance a full WOPL 700B, PL4000, JBL system. Though, that other equipment is nice, maybe you want two systems. Going to be expensive getting that Marantz recapped and aligned, and Bose driver surrounds replaced if needed. And, that Bose equalizer is most probably due a recap also. Tools? Your going a need a good temp controlled solder station, AND, a good desoldering station. Not cheap. Plus dozens of hand tools and a well lit long term work space. This could be the start of a great hobby and learning experience if so inclined and have time and funds. Just be aware that you will make mistakes, we all did and most probably still do. I make lots of them trying to learn. Read, read, read.
 

ALLENWERK

New Around These Parts
Joined
Oct 10, 2019
Messages
12
#13
At the very least get the DCP installed in the 700B by yourself or Hawthorne Audio. The 4000 could be the issue of low output on one channel, as these preamps suffer from bad solder joints and connections between the multiple boards inside. What did Hawthorne Audio say? Try swapping the interconnects around to determine where the problem is. Just don't use those beautiful JBLs until the issues are fixed. Maybe pickup some cheap speakers at Goodwill. If it was me, I'd sell the other equipment to finance a full WOPL 700B, PL4000, JBL system. Though, that other equipment is nice, maybe you want two systems. Going to be expensive getting that Marantz recapped and aligned, and Bose driver surrounds replaced if needed. And, that Bose equalizer is most probably due a recap also. Tools? Your going a need a good temp controlled solder station, AND, a good desoldering station. Not cheap. Plus dozens of hand tools and a well lit long term work space. This could be the start of a great hobby and learning experience if so inclined and have time and funds. Just be aware that you will make mistakes, we all did and most probably still do. I make lots of them trying to learn. Read, read, read.
Thank you, George!
Hawthorne didn't say there was any major issues, or recommend anything further. So, at the time, I wasn't sure what to specifically ask.
I am reading through the forum as suggested and becoming more enlightened, this is a great place. And, I think this will be a challenging yet rewarding new hobby for years to come.
 

marcok

Chief Journeyman
Joined
Jun 9, 2014
Messages
773
Location
Milan Italy
Tagline
I'm very curious about any tech item
#14
Find the guilty : PL 4000 or PL 700B .
Simply reverse L and R channels at output of PL 4000 or at input of PL 700B .
Ciao
Marco
 

George S.

Chief Journeyman
Joined
Feb 18, 2020
Messages
694
#15
Thank you, George!
Hawthorne didn't say there was any major issues, or recommend anything further. So, at the time, I wasn't sure what to specifically ask.
I am reading through the forum as suggested and becoming more enlightened, this is a great place. And, I think this will be a challenging yet rewarding new hobby for years to come.
That PL4000 might have checked out fine on the bench, then the vibration of bringing it home caused it to malfunction. Do some reading about that models issues. Also, do a search on eBay for that model. There is a guy I think in TX that refurbishes them, has some interesting info, guess there were two versions of the 4000 series 1, below a certain serial # he won't work on. I'm at work now and can't be more specific due to time. Seen where they put a piece of foam between the vertical boards and top cover to keep continuity with the horizontal board. Something to look at and think about.
 

Skratch

Chief Journeyman
Joined
Dec 27, 2011
Messages
649
Location
Huntley Il.
Tagline
Life is short, so take your time
#16
Putting a White Oak driver board and changing the outputs to MJ21196 would be a good start for your 700B.
 
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