Philips CD104 tweaks

[JeroenR]

Originally posted by poynton
Hi.

This may work...

But I have not tested it....

I don't know what the ripple would be like.

It also requires another cap across the output ?

Both halves are working as full wave doublers.
The output of 1 is sat on the output of the other.

I dont think it will go BANG !

Andy

Hi Andy,

I'm going to try your circuit this weekend.

I'll try to deal with the ripple later, first thing is getting the 100V from the player's transformer.

Thank you very much for the help. I'll let you know about the results asap.

Jeroen

[poynton]

Hi.

I just looked through the many diagrams I have downloaded over the last fer months.

I came across this from M-F.

This is powered from a dual [ + / - ] supply .

I wondered if JeroenR could adapt the idea to his tube output stage?

Andy

[JeroenR]

Originally posted by poynton
Hi.

I just looked through the many diagrams I have downloaded over the last fer months.

I came across this from M-F.

This is powered from a dual [ + / - ] supply .

I wondered if JeroenR could adapt the idea to his tube output stage?

Andy

Hi Andy,

Thanks for the suggestion.

The diagram looks like two voltage doublers with one of the supply woundings to ground. The cd104 transformer has a center earth tap so I can not connect one of the supply lines to earth. Perhaps there is a trick....

I saw the double transitor setup on a tuner-mod site. Doesn't that cause a voltage drop over the resitors?

Funny thing though. Add tubes and the sound improves? Well, if it sells who cares.

I must admitt that I looked a few times at your previous diagram but have difficulties understanding. Too little experience I'm afraid. I will redraw the diagram a few times, perhaps that helps.

Jeroen

[poynton]

Originally posted by JeroenR


Hi Andy,

Thanks for the suggestion.

The diagram looks like two voltage doublers with one of the supply woundings to ground. The cd104 transformer has a center earth tap so I can not connect one of the supply lines to earth. Perhaps there is a trick....



Jeroen

Hi.

The part I wanted you to look at was the way the supply lines were connected NOT the power supply itself.

It uses a supply the same as you originally did ie. +b, gnd, -b

You may be able to adapt you design in this way?

Andy

Ps did you post your tube design? If not, please post and I will have a look.

[JeroenR]

Hi Andy,

Still looking at your last suggested diagram.

What happens if you connect two voltage doublers after the second diode. Will both branches be pushing it to a double voltage (again)? With the 104's center-earth it could then be symtrical around that centre tap and I have my earth.

Or is this complete cr..?

Jeroen

[poynton]

Originally posted by JeroenR
Hi Andy,

Still looking at your last suggested diagram.

What happens if you connect two voltage doublers after the second diode. Will both branches be pushing it to a double voltage (again)? With the 104's center-earth it could then be symtrical around that centre tap and I have my earth.

Or is this complete cr..?

Jeroen

It is complete. should give around 100v+

andy

[JeroenR]

Originally posted by poynton




Hi.

The part I wanted you to look at was the way the supply lines were connected NOT the power supply itself.

It uses a supply the same as you originally did ie. +b, gnd, -b

You may be able to adapt you design in this way?

Andy

Ps did you post your tube design? If not, please post and I will have a look.

Do you mean to make the earth for the tube circuit floating? A virtual earth.

[JeroenR]

Originally posted by JeroenR


Do you mean to make the earth for the tube circuit floating? A virtual earth.

A negative earth I mean.

[poynton]

Originally posted by JeroenR



A negative earth I mean.

Hi.

I think you are a little confused.

On the diagram below,

C1, C2, D1, D2 form a voltage doubler

C3, C4, D3, D4 form a second doubler

The voltage at the junction of D4, C4 is 25vAC doubled [ approx. 70v ]

The voltage from the other doubler will also be approx 70v.

Hence the voltage at the output will be approx. 140v [peak off load ]. This is measured between the existing ground and the junction of D2 and C2 [B+ in the diagram ].

The ground is the existing ground in the cd-player. It is not floating!


========================================


Refering now to the M-F circuit.

Ground is ground !!!!

The circuit has a B+ rail and a B- rail plus ground.
[ think op-amp power supply ]


=======================================

Please post your proposed tube circuit and I will try to explain with pictures.

Andy

[JeroenR]

Originally posted by poynton



Hi.

I think you are a little confused.

On the diagram below,

C1, C2, D1, D2 form a voltage doubler

C3, C4, D3, D4 form a second doubler

The voltage at the junction of D4, C4 is 25vAC doubled [ approx. 70v ]

The voltage from the other doubler will also be approx 70v.

Hence the voltage at the output will be approx. 140v [peak off load ]. This is measured between the existing ground and the junction of D2 and C2 [B+ in the diagram ].

The ground is the existing ground in the cd-player. It is not floating!


========================================


Refering now to the M-F circuit.

Ground is ground !!!!

The circuit has a B+ rail and a B- rail plus ground.
[ think op-amp power supply ]


=======================================

Please post your proposed tube circuit and I will try to explain with pictures.

Andy

Hi Andy,

Had some more time to look at the diagrams. I now see the errors in the first (wrong earth, shorting caps, that was silly). Attached are two diagrams, yours (V2) and the symetrical (V1). If I understand you correctly V1 will give 100V and V2 will give 140V. What will now give the most stable voltage (least ripple)? Also, in V2 the last cap C2 is connected to C4. Is this needed, could it be connected directly to earth?

What I meant by the virtual earth; the tube circuit sees from plate to tube-earth let's say 40V because plate is at 20V and tube-earth is at -20V and of course the tube-earth is not connected to the real earth. (or am I understanding the X10 diagram incorrectly?)

In the meantime I'm going to build V2 as I have more trust in your design then in mine (understatement).

About the tube circuit, I posted the thorsten design somewhere in this thread. I would be a fool to think I could improve with my knowledge hence the copy. Also in this thread I suggested a value for the R-C between DAC and tube-stage. I will update the diagram this weekend with values and repost. The kathode resistors will be a (hopefully educated) guess though as I have trouble getting tube data for voltages around 50V.

So, off to buy some caps for the powersupply and in the meantime enjoy the jazz-festival this weekend.

I'll post the results later.

Thanks for the help/education so far,

Jeroen