phase linear 400

[Vintage 700b]

well, you both have me convinced....neither would mislead me...
i wrote and asked for cheaper freight....42 is just too much....
if he helps me out a bit...i will buy that one...
thanks you guys....
super nice!!!

Hello Guys,
I also own a mint T151A Sencore. This is mine on a scale. The higher shipping is most likely due to the size and weight of the unit. With the box (double boxed in this case most likely), and all of the accessories, shipping weight may approach 12 pounds. These are big units.
PLEASE NOTE:
The link that George shared is ACTUALLY for a Sencore TF151 and not an "A" model. I agree with him that the internal boards are superior and much easier to service on the TF151A. I have had this one for decades, and it is very, dependable, and easy to use. In the link shared, the BOX says TF151A, but look at the actual unit, it is the TF151. The "A" on the box almost appears to have had the "A" blacked out. Just didn't want you to bid on something you may not want Gene.

 

[George S.]

Hello Guys,
I also own a mint T151A Sencore. This is mine on a scale. The higher shipping is most likely due to the size and weight of the unit. With the box (double boxed in this case most likely), and all of the accessories, shipping weight may approach 12 pounds. These are big units.
PLEASE NOTE:
The link that George shared is ACTUALLY for a Sencore TF151 and not an "A" model. I agree with him that the internal boards are superior and much easier to service on the TF151A. I have had this one for decades, and it is very, dependable, and easy to use. In the link shared, the BOX says TF151A, but look at the actual unit, it is the TF151. The "A" on the box almost appears to have had the "A" blacked out. Just didn't want you to bid on something you may not want Gene.

Oh crap, your right, it's not a "A" model. Thank you for catching that!
Gene, sorry, my error.
The "A" model has the PCB and is easy to service, the TF151 is a cluster of point to point wiring with buried components.
Look for a good "A" model.
Sheesh, that's what happens when I text while working.

 

[gene french]

Oh crap, your right, it's not a "A" model. Thank you for catching that!
Gene, sorry, my error.
The "A" model has the PCB and is easy to service, the TF151 is a cluster of point to point wiring with buried components.
Look for a good "A" model.
Sheesh, that's what happens when I text while working.

dont worry...i will clear it with you guys before i trigger it!!!!

 

[gene french]

If it is a PL14 board you are playing with Gene and cannot get the bias to go low enough, it is often that the bias circuit is the culprit.

You can try increasing R19 which should be a 680 or 470 ohm resistor on the PL14 board to 1K instead. That will allow extra base current for Q6 to help it come closer to saturation and bring down your high bias.

brought right channel down to 340 mv at min adjustment...looks good there...
left channel at 389mv...seems unaffected...

Hello Guys,
I also own a mint T151A Sencore. This is mine on a scale. The higher shipping is most likely due to the size and weight of the unit. With the box (double boxed in this case most likely), and all of the accessories, shipping weight may approach 12 pounds. These are big units.
PLEASE NOTE:
The link that George shared is ACTUALLY for a Sencore TF151 and not an "A" model. I agree with him that the internal boards are superior and much easier to service on the TF151A. I have had this one for decades, and it is very, dependable, and easy to use. In the link shared, the BOX says TF151A, but look at the actual unit, it is the TF151. The "A" on the box almost appears to have had the "A" blacked out. Just didn't want you to bid on something you may not want Gene.

THANK YOU!!!

 

[gene french]

If it is a PL14 board you are playing with Gene and cannot get the bias to go low enough, it is often that the bias circuit is the culprit.

You can try increasing R19 which should be a 680 or 470 ohm resistor on the PL14 board to 1K instead. That will allow extra base current for Q6 to help it come closer to saturation and bring down your high bias.

right channel at 340+ after warmup...with pot at minimum....
left channel seems unaffected...at 390...pot at min...

 

[gene french]

right channel at 340+ after warmup...with pot at minimum....
left channel seems unaffected...at 390...pot at min...

..

 

[Gepetto]

Lift 1 end of R19, the 1K you just changed ON THE LEFT CHANNEL and see how low the bias will go without any base resistor.

What was the value of R19 before you changed them to 1K?

 

[Hexis22]

well, you both have me convinced....neither would mislead me...
i wrote and asked for cheaper freight....42 is just too much....
if he helps me out a bit...i will buy that one...
thanks you guys....
super nice!!!

Gene,

Carefully look at the listing. This is not the “A” version. The Box indicates an “A”, but it’s blacked out with a marker.

The true “A” version has the model number on the front of the unit stating TF151A. This unit only states TF151.

Edit: Sorry, I missed the posts above.

 

[George S.]

And, indeed, they are large and heavy.

 

[gene french]

Lift 1 end of R19, the 1K you just changed ON THE LEFT CHANNEL and see how low the bias will go without any base resistor.

What was the value of R19 before you changed them to 1K?

they were 470 ....
1k fixed right side...
i experimented there left channel resistance...
got both to 348 set at mins...
after half hour of warming up...
gotta go to bank...
i can lift r19 when i return...
no adjustment left...
very little right...

 

[gene french]

And, indeed, they are large and heavy.

keep your eyes peeled please!!!
lol
broadening my horizons....

 

[George S.]

keep your eyes peeled please!!!
lol
broadening my horizons....

Yup, will do. Right now they're all priced too high. Mine was moderately priced, they were taking offers, offered them 1/2 of asking, they went for it.

 

[gene french]

maria and i went to the bank then to lunch....i left christine (evil car in a movie movie after which i named the amp) running ...
2 hours later...bias at 348 on both...right where i left it...i dont trust christine....
i will put her online tomorrow ...see if its gonna hold up...or maybe marvin will claim her....
lol

 

[gene french]

Lift 1 end of R19, the 1K you just changed ON THE LEFT CHANNEL and see how low the bias will go without any base resistor.

What was the value of R19 before you changed them to 1K?

should i do this check....or is what i have now working....i had to change the bias transistor on the left side and add more resistance to get it to fall into specs....the transistor checked good....but bias dropped 30mv when changed out after replacing 470 ohm resistor for 1k...
it immediately put the right side in specs...with a bit of adjustment ....the closest i could get the left side was about 360mv....i messed with that resistance until it stabilized at 348 or so....but, no adjustment for less bias....christine is evil....

 

[J!m]

Christine was a ‘57 Plymouth Fury I believe. I think the other dude had a ‘71 ‘cuda as well.

 

[gene french]

christine pulling mid bass duty in the system...
playing queen...
sounds nice...

 

[gene french]

the new smsl su9 dac/preamp arrived yesterday...
got it installed...quite impressive...it has functions / features i need to read more about...
keeps getting better and better...
waiting on the equalizer...i think i want a dh500 or another p230...along with another equalizer...
should i spend another fortune and upgrade the dodge music???
lol

 

[George S.]

Nah, keep the car audio stock as a benchmark.

 

[gene french]

i guess i should...lololol

 

[gene french]

spent the day rearranging the bedroom system...
the new dac would buffer under certain conditions....moved it to the bedroom...works fine...
the den tv has optical out...mbr tv has coaxial out...dont know...will experiment more...
mounted one of the spare pl400s (christine...the evil one) in the mbr system to replace the cambridge audio amp/receiver...it really didnt sound that good...it cooks with gas now...

a bit involved for me...as i have the tv.. chromecast...satellite decoder...ir blaster...network switch...dac ...preamp...dsp...lift mechanism...with two power strips...one strip is connected to battery/inverter...the other strip connects to shore power...the tv chromecast ir blaster satellite decoder is hooked to battery system strip...amp and associated hardware to shore strip...when we lose power we can still finish the movie...although with only tv producing sound...
the smart tv and chromecast are both fed with ethernet adapters and cable...no wifi there...more reliable...
and the new dac supports bluetooth...and has a remote!!!
wonder why the system buffered in the den...and not the bedroom...the den is also ethernet fed...
i will get it figured out...