PD1515 NPN Bipolar Transistors & its Data !

[Danieljohn]

In a Single Ended Circuit? Sir.
Something on these lines

In a Push Pull Circuit? Sir.
This is the exact circuit

A.In a Single-Ended Topology?
Kind of like this circuit but with a few mods.

A.I can't make out whether they are SE or PP by seeing Schematics. kindly let me know whether I was right or wrong about my guesses regarding the Amplifier Topologies?

B.Are AD 149 the biggest Germanium Transistor? Sir.
These are the biggest ones I have experience with.

B.You feel these are The Ultimate Germanium Transistors in any Amplifier ?

C.Or Amplifier Topology matters?

D.Does Single-Ended Germanium Transistor Amplifier exists?

Current work bench:

NAD 3020 x 2
NAD 208 x 1
Sony 29 Wega Trinitron CRT TV x 1
Keltron 14 BW TV x 1
Garrard RC 210 x 1
Pioneer PL12 x 1

on the way for repairs

6L6 mono tube amplifier x 1
Akai 1710L tube r2r x 1
NAD 3020 x 1

Lovely Collection ! Reflected Amazing AV Gear Sensibility.

I enjoyed Sony KV-HS38M61 Super fine pitch DRC CRT TV with Progressive Scan which made me a Videophile in a Blink.

 

[Danieljohn]

No, there is no danger in using higher voltage rated cap. Just follow the polarities correctly. Ditto for higher temperature caps.

The PSU can be viewed as an independent electrical circuit, and like any circuit a lower output impedance is better than higher.

Thanks Dear Jls001,
For putting a full stop to my search for The best Caps out ther for my Cosmic LAB-3000 Stereomaster Amplifier's PSU section.

 

[Danieljohn]

As you rightly mentioned, it was quite common for Philips circuits and Mullard circuits to get cloned in those times.

After seeing various Schematics of your Amplifiers I thought you might be having Philips 40+40 watts amplifier circuit diagram Dear Reuben Sir. If so kindly let me know.

Thanks in Advance !

 

[yugaaa]

You stillhave not confirmed if the amp worked after the buz39 was replaced .

 

[Danieljohn]

You stillhave not confirmed if the amp worked after the buz39 was replaced .

Restoration not yet Started Dear Yugaaa,
this Saturday it might start.
Thanks btw for your inputs regarding caps.

 

[reubensm]

After seeing various Schematics of your Amplifiers I thought you might be having Philips 40+40 watts amplifier circuit diagram Dear Reuben Sir. If so kindly let me know.

Thanks in Advance !

This is the only reference point which I have. Honestly I haven't researched Philips and Mullard circuits much as I am more inclined toward NAD designs. You will have to log in to view some of the attachments.

 

[reubensm]

A.I can't make out whether they are SE or PP by seeing Schematics. kindly let me know whether I was right or wrong about my guesses regarding the Amplifier Topologies?



B.You feel these are The Ultimate Germanium Transistors in any Amplifier ?

C.Or Amplifier Topology matters?

D.Does Single-Ended Germanium Transistor Amplifier exists?



Lovely Collection ! Reflected Amazing AV Gear Sensibility.

I enjoyed Sony KV-HS38M61 Super fine pitch DRC CRT TV with Progressive Scan which made me a Videophile in a Blink.

Actually that list of equipment is on my work bench for repairs. Currently working on repairing these

 

[Danieljohn]

This is the only reference point which I have. Honestly I haven't researched Philips and Mullard circuits much as I am more inclined toward NAD designs. You will have to log in to view some of the attachments.

A.Kindly have a look at the attachment.

B.So kindly post that attachments here.

C.New Acoustic Dimension Amplifier seems very similar to Cosmic LAB-3000 Stereomaster Amplifier like low impedance stability.

Thanks in Advance !

 

[reubensm]

There are a lot of different versions of the Philips 40 watt amplifier on there. I use my HFV credentials to log in

 

[Danieljohn]

There are a lot of different versions of the Philips 40 watt amplifier on there. I use my HFV credentials to log in

My issue was 3rd part.
I didn't receive confirmation email from diyaudio.com.
The Original Philips 40+40 watt is what required actually even if ther are lot of refined versions exists.

 

[jls001]

A.Really? a Darlington? Is this type of Transistor can be used wher bipolar transistor are implemented ?

B.Is Darlington superior to Bipolar?

A Darlington Pair is made up of two bipolar transistors. It has high current gain (~product of the current gains of the two component bipolars). So to answer your question, it's superior to a regular bipolar in current gain, but whether substituting a regular bipolar with a Darlington will be beneficial will be decided by the function of the original bipolar. It's certainly not a straight swap. B-E junction voltage drop of a Darlington will double compared to a single and that must be taken into account in the overall circuit design.

 

[Danieljohn]

whether substituting a regular bipolar with a Darlington will be beneficial will be decided by the function of the original bipolar.

In my case it is 2N3055HV Dear Jls001.

It's certainly not a straight swap. B-E junction voltage drop of a Darlington will double compared to a single and that must be taken into account in the overall circuit design.

Ok if I open up the cover of PD1515 will you be able to recognise whether it's a Bipolar or Darlington?

Thanks Jls001 !
For valuable explaination.