Sutton's Phase Linear, White Oak 500

[laatsch55]

Thought I would go with some LED meters like what Ampslabs sells, with a clip indicator, like that would ever happen.

 

[laatsch55]

Mark, have you noticed all our favorite small signal transistors are going obsolete, even th 5087's arte end of life. So I put in a Mouser order, 1000-5087's, 500-TIS-97's, 500-2N6517's, 200- 2N3439, 200- 2N5416's and some 21196's.

 

[laatsch55]

Wish these weren't Darlington---MJ10008

MJ10009 MJ10018
MJ10019

20 AMPERE
POWER DARLINGTON
TRANSISTORS
400-500 VOLTS
175 WATTS
50 AMPERE
NPN SILICON
POWER DARLINGTON
TRANSISTORS
400 AND 500 VOLTS
250 WATTS

 

[mlucitt]

I wonder if your order and my smaller order will cause them to source additional stock?

I saw some Darlington spec sheets the other day and they look good, basically an emitter follower pair that shares a common collector and they provide gain up to 2400. They have been around since 1953 thanks to Sidney Darlington. They have more phase shift at higher frequencies than conventional transistors but I wonder if it would be obvious at 20kHz?

 

[laatsch55]

What did the curve look like??

 

[mlucitt]

I looked at the MJ10012. It is a NPN Power Darlington, 10A, 600V, 175W, TO-3 case device. The gain on those bad boys wa 300-550. There was no phase curve, but the power was impressive if you can keep them cool. They are used for automotive ignitions just like the old Delco XPL909 devices.

 

[laatsch55]

Weren't the XPL-910's Darlington's??

 

[Skratch]

Yes, The XPL 910 are Darlingtons

 

[laatsch55]

Another PL NUT!!!!! YEAHJ!!!! Fill us in Dude!!

 

[mlucitt]

I could not find a datasheet on the XPL 910 because that was a Phase Linear part number stamped on some unknown device, maybe it was a DELCO DTS4072 or DTS4074 (TRANSISTOR, BJT, DARLINGTON, NPN, 600V CEO, 20A Ic, TO-3). Anyway, the Darlingtons were not used for long in PL700 production units probably due to variations in the device specs at high current levels resulting in unacceptable distortion due to uneven common emitter gain (hFE) between devices in the both totem pole sections unless they were carefully matched.

The newer devices are probably manufactured with tighter tolerances and matching off the shelf devices might prove much easier or not necessary at all.

 

[laatsch55]

The newer devices are probably manufactured with tighter tolerances and matching off the shelf devices might prove much easier or not necessary at all.




In Darlingtons??

 

[Skratch]

I have had Phase Linear since the early 70's, My original one is still cranking away just like the day I bought it new. I have purchased 2 more on E-bay. The first one I got the guy said it didn't work but all the lamps were burned out. Put a LED kit from White oak and cleaned it up. Put a 40 amp bridge and 20,000uf cap kit from Joe in it. Put it on a scope and wanted to see what it could do. It clipped at 48 volts, sounds great for a 129.00 plus caps and light board. The last one was not as good. The entire right channel was toasted Bias transistor, 2 of the emitter resistors and the right side of the driver board.

 

[laatsch55]

Is this Mark???

 

[Skratch]

Yea Lee, I stripped all the resistors and diodes off the output section and gave it a good cleaning. Parts from Mouser should be here on Friday. I was planning to clip the ground from the speaker terminal and run 2 grounds from the ground bar, 1 to the driver board and the other to the inputs. Am going to put new caps on the board coming from you and the back to back diodes on C6. Also should I add the .33 and the .0015 cap in the power supply. I read somewhere to change C6 to 470uf or is that just for the White oak board.

 

[laatsch55]

Mark, the board I'm sending also has 2 care packages in it with: 2 matched TIS-97's, a TIS-93, a MPSA-93, 2-2N3439's, 1-2N5416, 2-470Uf at 50 volt, 2-47uf at 100 volt, 2-47uf at 63 vollt, 2 back to back diode pairas, 2 large heatsinks, 2-1304's, 2-1305's. The caps on the bridge should be .01at 400 volt polyester self healing film caps.

 

[laatsch55]

the C6 mod and the back to back 1N4148's work as well on the pl14 board as on the White Oak board. Same gains, no latchup at turnon and improved low frequency response.,Yerp.

 

[Skratch]

Lee, The .33 and .0015 caps are after the filter caps. the 2 caps .33 go across the B+ and B- on the right output section. The .0015 cap goes on the B+ only on the left output section. On the print they are C 22,23 and 24. Also what do you think about lifting D9 and D10 to disable Q8 and Q9 in the protection section.

 

[Skratch]

On the .33 caps they go from B+ to ground and B- to ground on the right channel. The.0015 cap goes from B+ to ground on the left channel. I have 1 amp that that has these. The 2nd amp only has the .33 caps on the left channel. The 3rd amp does not have any. Was wondering if this a vintage thing because the last amp is a 400 watts RMS face plate and only half the rear heatsinks.

 

[laatsch55]

It could have been swapped around to Mark. The 4 single heat sink indicates an early Ser I. The grounding caps, 22,23, 24 I believe to dump any inducted hum, loops rfi, etc. I have not been including those on my White Oak restores. It appears Joe's improved grounding scheme and being able to ground each channel as well as Joe's layout does not necessitate the remounting of those caps. Now that being said, some one who knows a lot more than I do is welcome to shoot me down in flames.

If you are talking about the cap;s on the the output bars, those were to eliminate any stray inducted bad things due to the lenghth of the output wiring.

 

[Skratch]

Cleaning out the thermal grease that is everywhere. Whoever put the outputs in this one must have used a gallon. What do people use to clean this stuff out.