Just Registered Here

Gepetto said:
All of Marks videos are posted on this forum site
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And I’ve been thinking about scrapping the YT account for a while, possibly going to Rumble instead. Fed up with the commercialism on YT. I did these for fun, not to be a framework for car insurance ads.

Unfortunately, there’s the issue of “reach,” the fact of the huge numbers who watch YT over other platforms would limit the number of people who stumble upon my videos by accident or do a search for “Phase Linear.” Not that I’m seeking to go viral, and I’m just a schlub hobbyist, but I do have more than a rudimentary knowledge of what I’m doing and I target people who know far less. My aim was to get the people who don’t have the testicular fortitude to pick up a soldering iron and get them to undertake a satisfying project.
 
MarkWComer said:
And I’ve been thinking about scrapping the YT account for a while, possibly going to Rumble instead. Fed up with the commercialism on YT. I did these for fun, not to be a framework for car insurance ads.

Unfortunately, there’s the issue of “reach,” the fact of the huge numbers who watch YT over other platforms would limit the number of people who stumble upon my videos by accident or do a search for “Phase Linear.” Not that I’m seeking to go viral, and I’m just a schlub hobbyist, but I do have more than a rudimentary knowledge of what I’m doing and I target people who know far less. My aim was to get the people who don’t have the testicular fortitude to pick up a soldering iron and get them to undertake a satisfying project.
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Just started watching your 700 series II project so if the YT account goes away, let me know if I can watch them another way (I saw the 400 series in the forum post looks like it's available on the White Oak site).

I wasn't sure whether to mention this in the introduction post or wait to start a proper thread. I'm somewhere in the middle with electronics. I love to work on stuff but it's tube guitar amps and/or studio gear. If it gives any context, I built an 1176 Blue Stripe compressor (but didn't understand the schematic at the time - now I understand a lot more but that was early 2018), just followed the PCB and instructions and got the job done. Since then I've managed to bias and service my tube guitar amps without zapping myself. Still have to repair the RangeMaster boost pedal the fellow in Germany sent me a module to install. Anyhow, soldering irons don't scare me away.....

But I don't have the test equipment for guitar amps let alone hi-fi gear that any pro or even semi-advanced hobbyist would have, and still do everything with my Fluke meter. No oscilloscope, no isolation transformer, no signal generator, no Variac, etc. I use a voltage attenuator to cool off the insanely high line voltage in town (and get the amps happy back around 115-117vAC) but it's not a Variac, just a voltage attenuator. I do use a light bulb current limiter when working on guitar amps though, until it's time to bias the output tubes at least. I guess I should be more scared of tube circuits than solid state amps considering the voltages (I've registered 460vDC on the plates of some of my guitar amps), but I understand soldering transistors and ICs are much more heat sensitive than carbon comp resistors in tube guitar amps! Since I managed to not run into any major disasters building the 1176 or mic pre though I'd probably be fine with it.

I built the 1176 and then stopped since the schematic seemed so complex that I thought I'd be better equipped to come back to things later on after understanding how a tweed Champ (then Dexlue, then Deluxe Reverb, etc.) works. Now that tube guitar amps make a ton more sense and I have some real-world experience and success with simple repairs, etc., it still remains to be seen if White Oaking my 700B is biting off more than I should chew at the moment.....if so, again, I'm in no hurry. But this place looks interesting all the same so I'm reading through the archives and starting to research things at least.

I saw on the White Oak site that it says test equipment and "nerves of steel" are necessary for the advanced jobs (backplane in particular). What would I really need? Variac, scope, signal generator? Anything else?

However it unfolds remains to be seen, but I am intrigued by the possibility of a WOPL.
 
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As mentioned, you should be able to successfully complete a WOPL assembly with a Variac, dim bulb, and a quality 80-120W soldering iron.

For the backplane boards, a 3mm chisel tip, 80W iron (minimum), tapered springs, and lots of patience while soldering PEM nuts will get you through a successful assembly.

Also, several options exist on the forum for recovering issues if you run into a wall during assembly, myself included. Assuming you do not physically damage the PCB.

It’s a very rewarding project once completed.
 
I keep thinking about doing this. Thank you all for the great welcome and advice. To be honest I've never even hooked up the 700B (not even once) since receiving it in 2018, because I was scared off by the stories of "Flame Linear" and blown speakers, and then after I moved, the amp was simply too heavy to carry up two stories from my basement to hook it up to anything!

I received an email recently from the person who gave me all the stuff that answered some questions I had about the history. It was used by him at low to moderate volume until 2005 when it went into storage. I grew up in the Pacific Northwest and he was a patient of my Dad's who liked me and so he gave it to my Dad to give to me before the guy moved to England. The email recently received confirmed the amp was purchased in Seattle where he picked it up later on as the second owner.

Quote, "the items were never shipped when I owned them. I picked them all up personally and took them to your Dad when I cleared the house. The 700B is so heavy I think you'd know if it had been dropped! It certainly was not shaken in any long-distance transit and was almost certainly purchased new in Seattle where I picked it up." When I get some more time I should snap some pictures of all the gear but it all looks really clean/in great shape cosmetically. That said.....part of the complete WOPL rebuild includes the chassis too, and the 700B is what seems most promising for whavever comes of all this stuff moving forward. Time will tell I suppose.

He didn't remember exactly when he purchased any of the items but told me that in the early '90s when he realized "Bob Carver divorced and developed equipment under his own name, I realized the Phase 1 items I admired wouldn't be available again so I started buying from ads and even advertised in the Seattle Times. Surprisingly I got some responses from people who had sets and wanted to sell as job lots. I finished up buying a pile of different units including 400 amps, preamps, a tape player, an FM unit and a record player but only one 700B....

The cassette tape unit worked well until a rubber belt broke although it had too many other features to be practical."

That's the Model 7000 tape deck in the stash he gave me as well. I had it for a few months with "Nakdoc" before he retired (his shop used to be 7 minutes from my old apartment and was then about 15 minutes from the house later on when I moved) but he didn't have time to get to the 7000 before the doors closed so no restoration work was done on it. Interestingly, right before this past Christmas we got in touch again over the Internet, and we were going to try to get together (he offered to look at the heads to see what kind of shape they're in) but of course then I left town for an extended stay with family and it didn't happen (yet, at least).

In an ideal scenario, I'd have the deck restored and use it for myself but as of right now I still don't know.

From reading the forum archives, it seems that the 4000 preamp (it's a series 1 with the joystick) is not regarded well, and that shipping it usually just leads to more cracked solder joints than before. The 4000 he gave me was serviced in 2014 (the work invoice was kept in the original box) but not fully. "10+ capacitors need to be replaced" is on the invoice next to "customer has decided not to repair at this time." The work that WAS done lists "Repaired the main board, replaced power transistor, repaired cold solder joints, cleaned the controls and switches."

White Oaking the 700 seems attractive since I've never had any high-end hi-fi gear (I'm still using a Sony N110 from the '80s or '90s with bookshelf speakers!). A few years ago I did pick up an APT Holman and had Vince at AudioProz do a full upgrade/restoration on it around early 2021. The APT was a big improvement but obviously I never had any high-end power amps (just that N110 and a bunch of various cheap AV receivers).

At some point I should probably hook up the 4000 anyhow to see what state of functionality it may be in or not. I do have a love for electronics hobby work and actually find soldering FUN (gasp) but realistically, is it worth the time to try to keep a 4000 running or is that just counter-productive and pointless given the design flaws I've read about?
 
My "restored" 700b worked when I bought it last year, but it made a farting noise when I pressed it into service a few months ago so......

The White Oak job makes it into a high end amp. I did my 400 4 fin back in '22 and it's so good I sold that Dynaco ST70.
 
Sean,
Two thoughts come to mind after reading your very detailed posts. First, I have an older, WOPL upgraded, PL700B (S/N 1705) that I use every day in my main Audio System (upgraded Phase Linear 2000 preamplifier and Carver "Amazing" speakers) for background music streamed from space (XM Radio). Also, I will occasionally listen to a CD of Classic Rock at "Police Responding" levels (referred to here on the Forum as "Mach 10").
I have completely forgotten how wonderfully special this amplifier is because I treat it like a Sanyo integrated amplifier. My PL700B is in the optional Phase Linear wooden case and I keep it cool with two 5" Boxer/computer Fans wired in series so they run at half speed in order to be completely noiseless. This piece of Power Amplifier history has just worked flawlessly every day for the past ten years!

Second, regarding the Phase Linear 4000 (Joystick) preamplifier. I would suggest that you try it and see if it works for you, it might work fine. However, if it does not, I would not spend any money on it. And when it dies, drop it off at Goodwill and take a $400 tax credit. Replacement preamplifiers are the Phase Linear 2000 (with some upgrades), the Phase Linear 4000 Series II, the somewhat rare Carver 4000t, or if you want to ruin the 1980's vibe; you can shop around for an Acurus L10 or L11 preamplifier. They seem to be all the rage here these days.

Your other Phase Linear audio devices are good for tinkering and conversation pieces, the real guts of your system is the combination of preamp and power amp.

And, you will want to invest in a 10 Amp Variac or Autotransformer and you will want to assemble a Dim Bulb Tester (DBT) before you plug in your PL700B amplifier for a pre-upgrade test. The DBT instructions are in another Phoenix Forum thread or on the Internet.

Good Luck
 
mlucitt said:
Sean,

And, you will want to invest in a 10 Amp Variac or Autotransformer and you will want to assemble a Dim Bulb Tester (DBT) before you plug in your PL700B amplifier for a pre-upgrade test. The DBT instructions are in another Phoenix Forum thread or on the Internet.

Good Luck
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Thank you for this! As I look out ahead, realizing I would need a Variac, I had been wondering what to start looking for. Thanks for mentioning the 10-Amp so that I didn't get something smaller or dinkier just because I didn't know any better. This is helpful information.
 
I guess I have big hairy ones...(or I'm an idiot :eek::eek::eek:) I did my WOPL without the Variac...only used the dim bulb on initial power up but thanks to the quality of Joe's kits things went well.

Good luck with your project and you have come to the right place for expert advice, these guys are GREAT!
 
Question: Any specific recommendations on Variacs aside from a 10-amp or more? As I said in the OP, the electronics hobby began because I'm an old tube amp guitar player, so ideally whatever I wind up with for the 700 rebuild would be something I'd keep around forever when working on guitar amps. When I type in "Variac" I get all kinds of search results of course, ranging from really cheap to fairly expensive stuff.

Anything to look out for when browsing for older units?

I'm looking at some listings on Reverb and eBay for the Staco 3NPN15 (rated for 15-amps!).

Or would you advise just getting something new?
 
AnalogGuitarist said:
Question: Any specific recommendations on Variacs aside from a 10-amp or more? As I said in the OP, the electronics hobby began because I'm an old tube amp guitar player, so ideally whatever I wind up with for the 700 rebuild would be something I'd keep around forever when working on guitar amps. When I type in "Variac" I get all kinds of search results of course, ranging from really cheap to fairly expensive stuff.

Anything to look out for when browsing for older units?

I
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well, you did buy vintage amps????

lololol
 
74sdta said:
Welcome!

Take a look at these - https://www.sci-bay.com/product/staco-model-3pn1210-0-120-vac-12-a/

No affiliation - I bought mine from them, back when I was looking. The unit I received is better than the pictures they have posted for some.
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Thank you!

Since scopes have been mentioned earlier in this thread......

If I'm going to buy a scope would I just be better off to buy one of the new digital storage ones? One of the sub $1,000 Rigols or an entry-level Tektronix? What do those of you with experience and wisdom suggest? A scope would have been useful last year when finding ground noise in a guitar amp the hard way....I got close to buying an old '80s Tektronix at the time but never did....

Anything in particular I should be looking for (or avoid)?
 
74sdta said:
No affiliation - I bought mine from them, back when I was looking. The unit I received is better than the pictures they have posted for some.
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Those are good prices for autotransformers. Hopefully, shipping is not too bad.

For Audio (and guitar) work you do not need to go above 100MHz for the oscilloscope speed. Even a 50MHz unit will work just fine. As the speeds increase, the price goes up quickly. Two channels is the norm, you can pay more to get three or four channels, but why?
The digital oscilloscopes are nice and they have some amazing features but that can be difficult to repair. The analog oscilloscopes are becoming antiques now, so be prepared to replace some capacitors and maybe even some tubes, but the brand names (Tektronix, Leader, Hewlett-Packard, and BK Precision) are well-built and are still reliable.
Also, the military oscilloscopes (AN/USM-117C by Navy, AN/USM-425 by Tektronix, and AN/USM 488 by Tektronix) are rugged and simple to operate.
This is a good place to start looking:
http://www.theoscilloscopeshop.com/
 
I started with a very cheap working HP and a even less expensive matching parts unit. But this was before shipping got so expensive. Many of the old CRT scopes are very large. Maybe look local.
Then I bought a new digital Siglent to help fix the old HP and have a second unit.
Lots of cool features in the new digital equipment, that the old equipment doesn't have.
 
Over 365 days later. Parents just brought a ton of stuff out to me in a trailer, along with some electronics equipment (as I was sourcing electronics equipment easier back in the Pacific Northwest than in greater Nashville over the past year).

Since last year I got two oscilloscopes (BK Precision 2120B basically new/barely used, and a Tektronix 2235), bought a Variac (12 Amp, one of the old heavy Stacos that I went to pickup in Federal Way and then left home until parents came out for a visit), an Elenco signal generator (SG-9200 if I recall). Also have an isolation transformer here (this was all to enable my tube guitar amp hobby obsession that I've been studying for over a decade now) and dim bulb setup for guitar amps but not sure if I need to build anything else for a 700B re-build. The bench is slowly coming together.

Now I'm trying to decide whether or not to send the 4000 preamp away with them as I'm of the impression it's a load of troubles and not really worth much effort or bother. The model 7000 tape deck is a permanent state of "I don't know," as Nakdoc (who probably still hangs around Tapeheads) wasn't able to check the heads before he closed up shop and retired, so I don't know if I'm stuck with a paperweight or have a tape deck worth repairing and putting back into rotation. I have to start either getting stuff out of the house that won't ever be used or make good on what merits the space and storage.

The 700B is the only part of the system I'm certain about. Now the next wait becomes financial again, as I'll need to budget out for boards and figure out how far I want to go or not with the rebuild. But most of my projects turn into long terms ones so it's all good. Hopefully I'll have another update before another 365 more days slide by but at some point, I fully intend to make use of the 700.
 
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