Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thread

[speakerman1]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I'll have to listen to it again. This box set Lee is going to freak at these tapes.

Larry

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Due to the fact you actually "loaded" them??

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Uh oh.. got some trouble...

At first I was thinking it could be some resistance in my speaker paths, but it seems the left channel amp is having some difficulties. Just at relatively high volume – but basically it seems like it’s clipping way too earlier than it should (as I said before, I haven’t even come close to 0db). I verified it by swapping inputs and speakers… the trouble followed and stayed with the normal left channel amp.

Do you think I should pop off each tranny on the left and reseat? Maybe one came loose in shipping?

 

[Web Police]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Could it be Chewbacca drool? Lee will get it figured out. Maybe he can probe it remotely, although Stuwee is the only one I know that can do that.

Sorry I haven't posted in this thread and the temptation was just to great.

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Jer, sorry Bud, I thought I answered that in the last e-mail!! Ok, where the hook up wires go up through the board there may be a shitty solder job on one of em. With the board still bolted to the chassis, go over each solder joint for the wires, wont take long and I was going to do that as I had this happen to me too. If that doesnt do it, one of the drivers may not be making good contact, take the 2 out forthat channel, there may be some white gease on em. Pinch the tabs in for the leads and reseat em. Those sockets were not the best.
And now the embarrassing part.............I totally forgot to de-oxit the pots. that could be it too.
And last but not least, check the 5 amp fuses.

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Howdy

I did a quick inspection and noticed that one of the terminals on the caps was just a little loose. Tightened that and retried.

I haven't done anything else yet (was thinking the lead coulda been the "quick fix"), but one thing I am noticing... the power indicator is dimming as if the power supply is running out of amps to drive the rest of the circuit. I can probably put a meter to it under load and check the rails for sag. I'm just wondering.... when that bridge went out, did you do a full retest? Is is possible that when the bridge went, it could have damaged something in the process?

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Jerry, after the bridge was replaced I tested to "Tales of the Inexpressible", "Vaccine",and "the God Particle", it was up to snuff on those. The power indicator does that idling if I remember right. You got a scope and stuff .....right??

 

[Gepetto]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Is the thermal cutout mounted on the chassis shot as a result of the bridge short circuit? Something to check out. It is wired in series with the transformer primary.

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

I know ya got a meter, let's check the bias on that channel, if it's all over the place we'll know it's output related.

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

We have a good channel Joe, so that would indicate the Thermodisc's are ok, cause they are in series.

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Joe, I gotta head back out in the field, we have one of our major water plants down. I'll be back in 2-3 hours. I leave Jer in your MORE than capable hands.

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Good luck Lee! Be safe!

Yeah, I'll check out the suggestions made tomorrow. A bit too late...

Trick is I'll have to "test", and that means "waking the dead" since I don't have a dummy load. Sooo.. bear with me a lil....

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

We have a good channel Joe, so that would indicate the Thermodisc's are ok, cause they are in series.

Well... maybe... I did experience some clipping on the right in earlier sessions, but it seemed to have stabilized. That may make some sense, because again... if it's dimming the power indicator well below "rated", then it's either drawing too much current somewhere or the line's being choked off before the transformer (the latter is only a theory... I need a skeezer one day of this puppy to inspect... )

Where do I measure the bias at, and what should it be (where to adjust, if not)?

 

[laatsch55]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Bias is measured at the ten ohm resistor on each transistor row on the chassis. They are under the emitter resistors and tie in from the collector bus bar to the common point of the emitter resistors for that row. Adjustments can be from .(point) .25 to .(POINT) .40 dc VOLTS. iDEAL IS .3 TO .35 THE ADJUSTMENT IS MADE BY THE BLUE POT ON THE TOP OF THE BOARD.

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Hold on.. lemme put my pants down so my butt-crack is showin, and get my best "plumber voice" on...

"Well hell.. there's yer problem RIGHT THERE!"

(look at the emitter resistor farthest away on the right side bank).

Not nuthin' I can't fix up. Time to warm up the irons...

 

[Elite-ist]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Would there have been a post on the board where the resistor lead is not connected, or just needs resoldering to the existing terminal?

Nando.

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

The right channel TO3 in the same position has it and it's own lead connected, so I'd say it should have been connected the same way on the left channel (which was "weak").

Got it buttoned back up and am listening now. But it's past midnight, so I can't quite fully test it (dee-vorce, anyone?? heheh). But it's at a comfortable level and the left channel is sounding pretty strong at this volume. So we'll have to see tomorrow afternoon if this did the trick (HAS to be it... it was like a car running on 5 outta 6 cylinders). With the emitter on that one transistor not having a strong tie point to the output, it was basically out of the game.

Damn... I better go watch TV, because I keep sneaking my hand near the volume, and thinking better of it.

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Of course I can't pull myself away .... it sounds so damn good.....

Lee... YOU DA MAN ... Joe.. YOU DA OTHER MAN....

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

The flatscreen was removed, the 300 watt incandescents removed, all wall hangings removed, AND LOOK AT THE METERS!!!!! That's on an amp that tested over 500 WPC!!!!
+2 DB on left, +2.5 DB on the right.!!!!!!!!!!!!!

AW JEEZZZZ!!!!!!!!!!!!!!

Damn... you know... if I EVER even get CLOSE to that, I'm gonna say these CV's are gonna get toasted!

Not to mention my eardrums. I should get an SPL meter to scare everyone, and myself..

 

[jbeckva]

Re: Jerry's " ONLY ONE IN THE COUNTRY" Phase Linear 700 Thre

Ok... chased away the wife and kid (hehe.. not really, they were heading out to do something or another).

Verdict - GOOD!!! Lee... I have no idea how you could even stand it halfway!!! I thank you, but my neighbors... probably not... heheheheh