Revisiting some "old" ideas from 1970's - IPS, OPS

[thimios]

I found 2N5088 ,I must ask Vallery if is it suitable for using here?

 

[vzaichenko]

I found 2N5088 ,I must ask Vallery if is it suitable for using here?

Hi Thimios,

2N5088 is ok for the purpose - it's a slightly "simpler" version of 2N5089.
Slightly less gain and very slightly more noise. Not important for this design though - this is not a mic amp or a phono stage

Datasheet for both of them is attached (ON Semi public access).

Cheers,
Valery

 

[still4given]

I'm using the MPSA18. Could you look at that please?

 

[vzaichenko]

I'm using the MPSA18. Could you look at that please?

Hi Terry, MPSA18 is virtually the same as 2N5088/89 - see the datasheet attached, it says "see 2N5088 for characteristics" Excellent option.

Cheers,
Valery

 

[Capt Grogg]

Terry,
What printer are you using,different mfg toners vary

 

[still4given]

Hi Valery,

Good to know I can leave them in place.

Hi Capt,

I use an HP Laserjet. I tried using a Brother and didn't get good results. The HP works great and was inexpensive.

 

[hahfran]

Hi
i guess downscaling to +- 35 volts rail for 50 watts is not trivial?

 

[hahfran]

Sorry, I should have been more clear. I first print out the image on a plain piece of paper. Then I cut a piece of the contact paper slightly larger than the image, peel the back off and cover that image with the contact paper and run it through the printer a second time. The image is now applied to the surface of the contact paper. Next, I center the board over the image, foil side down, and tape it in place. Flip it over and apply the iron on the highest setting for about 1 to 1 1/2 minutes until I see the paper begin to tan. (This part may take a little practice depending on the temperature of your iron). Next douse the board in cold water to set the toner. Now peel away the paper and you should be left with a clean transfer with little or no toner remaining on the shelving paper. I use the same process for transferring the silkscreen image.

Hi ok. I have read elsewhere about this transfer method. I manage to get the toner ( HP) on the board but found it is not a proper resist. I use HCL+H2O2.

 

[still4given]

Strange. I use 1 part muriatic acid and 2 parts hydrogen peroxide. The HP toner works perfectly. I etch at least one board each week, often more. I can't imagine why you are having an issue.

 

[vzaichenko]

Hi
i guess downscaling to +- 35 volts rail for 50 watts is not trivial?

It's pretty easy - I will give you the optimal values for +/-35V rails tomorrow.

Cheers,
Valery

 

[Idefixes]

Hi valery,
do you remerber, we discuss about a Parts Value / Vrail (35vdc, 42vdc, 50vdc... ) charts for tube version? If you had a little time...I will order some board of the Tube IPS.

Marc

 

[vzaichenko]

Hi valery,
do you remerber, we discuss about a Parts Value / Vrail (35vdc, 42vdc, 50vdc... ) charts for tube version? If you had a little time...I will order some board of the Tube IPS.

Marc

Hi Marc,

Thanks for reminding me
By the way, what exactly rail voltages are you interested in, so that I include them in the chart?

Cheers,
Valery

P.S. Ah, I see now ))

 

[hahfran]

Strange. I use 1 part muriatic acid and 2 parts hydrogen peroxide. The HP toner works perfectly. I etch at least one board each week, often more. I can't imagine why you are having an issue.

could it be HP has more than one kind of toner?
ok. boards with photoresist coating work fine.

 

[Idefixes]

Hi Marc,

Thanks for reminding me
By the way, what exactly rail voltages are you interested in, so that I include them in the chart?

Cheers,
Valery

P.S. Ah, I see now ))

Yes i have some trafo in 2x25Vac, 2x30Vac and 2x35Vac in stock...

Marc

 

[Idefixes]

Valery,

I want to order Ampliwire ECC88 what would be your choice between the 2 under....two layer as is it the same price....?

Marc

 

[vzaichenko]

Valery,

I want to order Ampliwire ECC88 what would be your choice between the 2 under....two layer as is it the same price....?

Marc

To be honest - I like the one with the ground plane (at the bottom)

 

[Idefixes]

To be honest - I like the one with the ground plane (at the bottom)

Ok so ground plane version validate....

Thanks Valery...

 

[still4given]

Speaking of the ECC88 Ampwire, IT SINGS!

 

[Idefixes]

Please Terry tell us more toward your whole experience in Slewmaster family...

 

[hahfran]

It's pretty easy - I will give you the optimal values for +/-35V rails tomorrow.

Cheers,
Valery

Very kind thanks. I am confused which post# is the actual schematic? with BJT OPS?