Mark goes at it again... just bought a PL700/II!

[MarkWComer]

Did you determine if the temporary shutdowns were heat related? In other words, caused by the thermal switches on the backplane? Mine did that once... Luckily, by reflex, I turned the amp down. Because when the thermal switches cooled a bit, the amp came back on with a vengeance!

NO! You misunderstand... I didn't have a shutdown- this is (was?) one of the original features of the PL700/II design, that if you DID overdrive, there would be a temp shutdown and the last three LEDs on the meter would flash. I was asking if that feature still existed with the WO upgrades.

I was asking for the sake of the meter board assembly video...

 

[MarkWComer]

Yep, that'll make you jump out of your skin..

That might make your bones jump out of your guts!

 

[Gepetto]

No, the meter works just like a meter does. If you overdrive the scale, the last (40th) LED will stay illuminated as long as the overdrive condition persists. When it subsides, the LED illumination walks down to the new output level.

 

[mlucitt]

NO! You misunderstand... I didn't have a shutdown- this is (was?) one of the original features of the PL700/II design, that if you DID overdrive, there would be a temp shutdown and the last three LEDs on the meter would flash. I was asking if that feature still existed with the WO upgrades.

I was asking for the sake of the meter board assembly video...

When you said temp shutdown, I think you meant temporary shutdown, I assumed you meant temperature shutdown.

 

[MarkWComer]

Video Section 5. Watch it quickly before the copyright removal (Pink Floyd "One Of These Days") and the LGBT8r@&Q community gets offended.
B-roll outtakes at 33 minutes...

 

[mlucitt]

Outakes - Your nose has been too close to the soldering iron...
Do you know the story of Pink Floyd's "One of These Days" recording?

 

[MarkWComer]

Do you know the story of Pink Floyd's "One of These Days" recording?

A few rumors. Supposedly they were PO at a radio DJ, and another that the vocal played backward was a warning to Syd to get him to stop all the acid he was dropping. That, and a few tech stories about the bass being put through an echo/reverb and multi tracking.

My favorite band, but can’t decide on a favorite album. I won’t play anything after “The Wall.”

 

[mlucitt]

A few rumors. Supposedly they were PO at a radio DJ, and another that the vocal played backward was a warning to Syd to get him to stop all the acid he was dropping. That, and a few tech stories about the bass being put through an echo/reverb and multi tracking.

My favorite band, but can’t decide on a favorite album. I won’t play anything after “The Wall.”

So, my understanding, according to Roger Waters, they went to the studio to record "One of These Days" and David Gilmour gave a roadie some money to get a fresh set of bass strings (they were full of dirt and sweat after several road shows). The roadie instead took the money and ran off with his girlfriend. Roger's bass had fresh strings (he is the bass player) and the bass produced a very 'twangy' sound. David's bass has a muted and dull sound, so the engineer panned each base to the left and right sides plus a mixed center channel. The two basses have different sounds and produced a unique blend that has never been duplicated. Listen to it and see if you can hear the difference, I can but I didn't know why until I heard this story.

 

[MarkWComer]

Outakes - Your nose has been too close to the soldering iron...

Oh, yeh... About that... I got that piercing to rebel against South Carolina culture about 22 years ago. The piercing parlor put a CBB (circular barbell) in it and I thought I looked like a pig at a slaughterhouse. Nevertheless, I had a point to make, and left it in until I moved to Pittsburgh. After some traveling around, came back to SC and a great niece showed me her septum piercing. Not wanting the ring, I remembered a guy at a bar I frequented in Baltimore, a Pacific Islander, who had an actual bone through his nose. So I found this metal spike online- it’s called a “septum tusk,” and started sporting that around town. I get mixed reactions (“so cool that a man your age...” “you look like the devil...”). My pastor’s wife loves it! Personally, it looks a bit wicked to me, and I like that.

I find pleasure in tossing bricks through the windows of societal norms sometimes...
The T-shirt in the video is a graphic of the psilocybin molecule...

I should have used it to pop my tits in the video. It is pointy enough.

 

[MarkWComer]

Section 6 video posted, covers miscellaneous parts (with part numbers!) and the BEAUTIFUL White Oak Audio chassis.
Surgery starts next week, no Leopard print dress in this one...

 

[Gepetto]

Great video Mark, as usual!

 

[mlucitt]

Mark, I like that Variac from the 19th Century...

 

[MarkWComer]

Mark, I like that Variac from the 19th Century...

It’s a beauty, eh? And it’s a HEAVY one! I think it came from the Frankenstein castle.

 

[MarkWComer]

Great video Mark, as usual!

Let’s see what I can do for the next one.
I think my niece has a green screen and I’ve been itching to see what I can do with it.

Hmmm... hedge clippers...

 

[MarkWComer]

I can’t find the original post about the new PL700 chassis anywhere. Admin: can you “sticky” that?

In particular, what happens with the ground pin- connect to something or not?
Orientation- ground pin toward xformer side or away (that’s an OCD issue on my part).

 

[laatsch55]

Do not hook the 3rd wire to ground. Unless someone has started doing it different. Ground loops can occur if any other component in your system has the ground attached ..

 

[MarkWComer]

Do not hook the 3rd wire to ground. Unless someone has started doing it different. Ground loops can occur if any other component in your system has the ground attached ..

Right. These amps weren’t designed with a line cord ground originally, just wondered if that changed. Single point (chassis) ground only, signal ground is completely separate.

Just czeching.

 

[mlucitt]

I can’t find the original post about the new PL700 chassis anywhere. Admin: can you “sticky” that?

In particular, what happens with the ground pin- connect to something or not?
Orientation- ground pin toward xformer side or away (that’s an OCD issue on my part).

Lee has a good point, but this discussion has been going on for years - hum or safety? Clearly, if your CD/DVD player is grounded, your pre-amplifier is grounded, and your PL700 II is grounded you may get a 60 Hz hum that will drive you crazy because it is being amplified along with Dark Side Of The Moon. But you are safe because an internal short in any piece of equipment (regardless of how rare this may be) will travel back along the ground wire to your power panel and disconnect the AC line at the speed of light (almost). Not many audio systems designed in the 1960's included 3-prong AC power plugs because few houses had 3-prong AC receptacles.

One way to handle this, and with a naked chassis it would be easier, is to connect the ground wire to a shiny spot on the chassis with some star washers, to get a good "bite" and connect no other amplifier wires to the chassis. That way, the ground loop is broken because there is no return path for any low-level spurious AC voltage that may be on the ground wire. Otherwise, ground the amplifier only if the CD/DVD and the pre-amplifier are ungrounded and both use two-prong AC power wires. This is why I lift the RCA input jacks off the short copper strip and keep them off chassis ground. No AC hum for me.

The jack for your power cord should be installed so that you can read the pin numbers on the inside/backside with the unit in the normal operation orientation. If the jack is mounted vertically, then you are on your own and the IEC may visit you unannounced and confiscate all your electronic equipment.

 

[Gepetto]

I do not recommend connecting the 3rd ground wire Mark. The PL amp was not designed to have a 3rd wire chassis ground so I keep it that way.

It is your amp so all I can do is to make a recommendation. The ground loops are all yours.

On the other question, let your OCD rule, no standard exists for that.

 

[mlucitt]

I do not recommend connecting the 3rd ground wire Mark. The PL amp was not designed to have a 3rd wire chassis ground so I keep it that way.

It is your amp so all I can do is to make a recommendation. The ground loops are all yours.

On the other question, let your OCD rule, no standard exists for that.

The grounding regimen comes from my years in the Navy. Saw too many men get shocked on ungrounded appliances and personal items that were brought aboard and not grounded. Of course, we lived on a steel ship. But the technician in me thinks that, just because your body is not well grounded to a metal hull, is no reason to have 120VAC running through your body.

All my SONAR gear was run through balanced and shielded armored cable, all the cabinets were bonded to the hull and each chassis within the cabinet was grounded. We checked grounds with a megohm meter annually to ensure no ground leaks. Old habits die hard, and I will never die from a live chassis. Thanks for your understanding my curmudgeoness.