Hi gianis, this might help:
http://www.mif.pg.gda.pl/homepages/frank/sheets/084/9/957.pdf
As you probably already know the 95x series of acorns were originally designed for radar use. The 955 has a full power bandwidth past 400 MHz. The socket is designed to be part of the circuit and requires special handling. What you could be experiencing is oscillation. My first try with a 955 had the same issue with microphonics. I replaced it with a 9002, an exact equiv on a different socket. The socket is soldered to a ground plane, plate and grid stoppers used and the LED-biased cathode bypassed to ground with a silver mica. Clean as a whistle to the (unfortunately low) 60 MHz limit of my scope. I'm a big fan of the sound as well. I'm thinking of giving the 958 a shot with NiMH batteries to power the filament. 1.25 volts at 0.1 amps, a perfect fit.
http://www.mif.pg.gda.pl/homepages/frank/sheets/084/9/957.pdf
As you probably already know the 95x series of acorns were originally designed for radar use. The 955 has a full power bandwidth past 400 MHz. The socket is designed to be part of the circuit and requires special handling. What you could be experiencing is oscillation. My first try with a 955 had the same issue with microphonics. I replaced it with a 9002, an exact equiv on a different socket. The socket is soldered to a ground plane, plate and grid stoppers used and the LED-biased cathode bypassed to ground with a silver mica. Clean as a whistle to the (unfortunately low) 60 MHz limit of my scope. I'm a big fan of the sound as well. I'm thinking of giving the 958 a shot with NiMH batteries to power the filament. 1.25 volts at 0.1 amps, a perfect fit.
Darling Amplifer
My good friend Tony Wong just completed a Darling Amplifer based on Bob Danielak's circuit.
Here's a back view showing the spk binding post and RCAs.. the output trannies are vintage Siemens/Klangfilm type encased in wood.
A shot of the internal wiring
My good friend Tony Wong just completed a Darling Amplifer based on Bob Danielak's circuit.
An externally hosted image should be here but it was not working when we last tested it.
Here's a back view showing the spk binding post and RCAs.. the output trannies are vintage Siemens/Klangfilm type encased in wood.
An externally hosted image should be here but it was not working when we last tested it.
A shot of the internal wiring
An externally hosted image should be here but it was not working when we last tested it.
Re: Darling Amplifer
Nice amp but it makes me feel like going for a swim
The Power XFMR and valves look nice and old. What does it use for output XFMRs? No volume control, I like the power amp approach. What preamp and speakers will it end up with? Also, what kind of power is it capabale of?
Cheers,
Shawn.
BTW said:
Nice amp but it makes me feel like going for a swim
The Power XFMR and valves look nice and old. What does it use for output XFMRs? No volume control, I like the power amp approach. What preamp and speakers will it end up with? Also, what kind of power is it capabale of?Cheers,
Shawn.
Re: Re: Darling Amplifer
Hi Shawn,
The output trannies are vintage Seimens/Klangfilm type, here a picture of it before being boxed up...
The single tube Darling puts out only 0.75W per channel, so high efficiency spks are recommended. The Darling amp is connected to a pencil tube preamp and spks are either a Coral Beta 10 or the Lowther PM2A in the Azura Front Horn.
Here's more info by Bob on his amp.
http://www.geocities.com/TimesSquare/1965/darling.html
TomWaits said:
Nice amp but it makes me feel like going for a swim
Cheers,
Shawn.
Hi Shawn,
The output trannies are vintage Seimens/Klangfilm type, here a picture of it before being boxed up...
An externally hosted image should be here but it was not working when we last tested it.
The single tube Darling puts out only 0.75W per channel, so high efficiency spks are recommended. The Darling amp is connected to a pencil tube preamp and spks are either a Coral Beta 10 or the Lowther PM2A in the Azura Front Horn.
Here's more info by Bob on his amp.
http://www.geocities.com/TimesSquare/1965/darling.html
Hi BTW,
Those are really vintage transformers. I'd love to have some of them in my shop. I'm particulary interrested in old transformers and vintage (pre-WWII) vacuum tubes. I'm planning to build really vintage amplifier (for the old times nostalgy and for the look, last but not least I want to bring in my speakers the vintage sound).
If I dare dreaming... a R-Type triode amplifier...
Thank you all (especially Giaime) whom spotted errors on my site and helped me correct them.
Regards,
ALEKS
Those are really vintage transformers. I'd love to have some of them in my shop. I'm particulary interrested in old transformers and vintage (pre-WWII) vacuum tubes. I'm planning to build really vintage amplifier (for the old times nostalgy and for the look, last but not least I want to bring in my speakers the vintage sound).
If I dare dreaming... a R-Type triode amplifier...
Thank you all (especially Giaime) whom spotted errors on my site and helped me correct them.
Regards,
ALEKS
Good evening,
Here's what I've been working at for some weeks. It is not finished yet but there's plenty of time to finish the work. It's better never to hurry up if you need to make something looking and working great.
The logo WASP (this is the name I gave to the amplifier) is hand made by me.
I didn't said this is a 6W electric guitar amplifier with overdrive.
And the interior:
Regards,
ALEKS
Here's what I've been working at for some weeks. It is not finished yet but there's plenty of time to finish the work. It's better never to hurry up if you need to make something looking and working great.
The logo WASP (this is the name I gave to the amplifier) is hand made by me.
I didn't said this is a 6W electric guitar amplifier with overdrive.
And the interior:
Regards,
ALEKS
Sorry,
A new member,
This is my first time post the photo, testing
This is my power amplifier
Class A1
32 Watt 3.3 % THD max power
Power Tube 4 X 300B (each channel)
Driver Tube 1 X 300B (each channel)
Rectifier Tube 6X 300B (each channel)
Total 22 pcs 300B
A new member,
This is my first time post the photo, testing
This is my power amplifier
Class A1
32 Watt 3.3 % THD max power
Power Tube 4 X 300B (each channel)
Driver Tube 1 X 300B (each channel)
Rectifier Tube 6X 300B (each channel)
Total 22 pcs 300B
An externally hosted image should be here but it was not working when we last tested it.
It won't sound half as good
I don't know quite what to say. I guess you're the real entomologist.
Can you explain the reason you went with such expensive triodes for power supply rectifiers when there are better and cheaper tubes made specifically for this purpose?
Nice clean construction. Looks really heavy, especially since there are two of them.
Can you explain the reason you went with such expensive triodes for power supply rectifiers when there are better and cheaper tubes made specifically for this purpose?
Nice clean construction. Looks really heavy, especially since there are two of them.
300B pre amp
This is my 300B pre amplifier
This is my 300B pre amplifier
An externally hosted image should be here but it was not working when we last tested it.
