Kriesler Radiogram refurbishment questions

lhalha · 31st March 2012, 04:33 AM

Hi all,

I have picked up a Kriesler radiogram model 11-104 designed in 1965 and manufactured around 1970 - It has an AM radio and a stereo Garrard turntable.

Everything works at the moment, but is it worth replacing any of the key components like transformers or valves with new ones of the same specifications?

I've removed the amp and tuner, and am planning on installing it in a new box as a simple standalone unit with RCA connections for a turntable and binding posts for the speakers.

Thanks

M Gregg · 01:44 PM

Hi,

I would change the power supply caps for new, however if you change other components like coupling capacitors (C19,20,21,22) possibly what looks like (C16 cathode bypas on the lower half of the 12AX7 I would change this!) the sound of the system will change. This is the same for transformers. Some people prefer the old component sounds. It depends what you want and why you bought this unit. You could change all capacitors with ? here is the question..Polypropylene are probably the best but again the sound may change and get brighter.

Probably a good idea to check the output tubes are not red plating if they look OK then it is a personal choice. Same with tubes if they are working OK.

Regards components if you want something better..
After listening to Ansar caps for the price and sound I would go with them if you want to upgrade with something better than standard then obbligato or clarity cap are good. Physical size needs to be checked because audio grade can be larger than a standard component. Might be a good idea to fit some bleeder (discharge resistors if non are fitted). Make sure the supply is discharged before you touch anything..I don't know if you have worked on tube equipment (it can hold charge). Make sure all earths are Good!
Remember if you change any resistors the working voltage has to be high enough. If you change anything in the radio section you may move the tuning and setup..
I would also change the mains cable and plug and ensure correct fuse is fitted.

Hope this helps.

Regards
M. Gregg

Ronsonic · 31st March 2012, 06:22 PM

The only things I'd say to do sight unseen are:

1 - cleaning
2 - electrolytic caps

For the cleaning get a can of Caig Deoxit D5. Do the tube sockets, control pots and switches all internal and external connectors. Just a short spray and exercise. If the pots and rotary switches are funky repeat as needed. Get a can of tuner cleaner or tuner wash for the big variable cap - flush generously.

For the electrolytic caps automatically replace any that are bulging or show anything leaking out of them. Beyond that either measure ESR or replace any that aren't doing their job, or just replace them wholesale. Lift off nuke from orbit.

If there are paper in oil caps check that they are actually blocking DC - those are often pretty leaky by now. You'll hear it when controls remain noisy no matter how clean they are. .

thevalvekid · 31st March 2012, 10:06 PM

I have the same little amp as my workshop amp.
Single ended 6M5, it's a lovely old thing.

Ronsonic is spot on.
Mine was full of Ducon wax caps, be sure to get rid of those.
Make double sure you replace the two caps across the power switch/volume knob.
If they short, they make a heck of a mess. Use appropriate mains rated caps here.

Also, keep in mind the OPT's only have a 15 ohm secondary tap.

31st March 2012, 01:24 PM	#2
M Gregg diyAudio Member Join Date: Jun 2010 Location: UK	Hi, I would change the power supply caps for new, however if you change other components like coupling capacitors (C19,20,21,22) possibly what looks like (C16 cathode bypas on the lower half of the 12AX7 I would change this!) the sound of the system will change. This is the same for transformers. Some people prefer the old component sounds. It depends what you want and why you bought this unit. You could change all capacitors with ? here is the question..Polypropylene are probably the best but again the sound may change and get brighter. Probably a good idea to check the output tubes are not red plating if they look OK then it is a personal choice. Same with tubes if they are working OK. Regards components if you want something better.. After listening to Ansar caps for the price and sound I would go with them if you want to upgrade with something better than standard then obbligato or clarity cap are good. Physical size needs to be checked because audio grade can be larger than a standard component. Might be a good idea to fit some bleeder (discharge resistors if non are fitted). Make sure the supply is discharged before you touch anything..I don't know if you have worked on tube equipment (it can hold charge). Make sure all earths are Good! Remember if you change any resistors the working voltage has to be high enough. If you change anything in the radio section you may move the tuning and setup.. I would also change the mains cable and plug and ensure correct fuse is fitted. Hope this helps. Regards M. Gregg __________________ What is the sound of one hand clapping? Last edited by M Gregg; 31st March 2012 at 01:44 PM.

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31st March 2012, 06:22 PM	#3
Ronsonic diyAudio Member Join Date: Mar 2012	The only things I'd say to do sight unseen are: 1 - cleaning 2 - electrolytic caps For the cleaning get a can of Caig Deoxit D5. Do the tube sockets, control pots and switches all internal and external connectors. Just a short spray and exercise. If the pots and rotary switches are funky repeat as needed. Get a can of tuner cleaner or tuner wash for the big variable cap - flush generously. For the electrolytic caps automatically replace any that are bulging or show anything leaking out of them. Beyond that either measure ESR or replace any that aren't doing their job, or just replace them wholesale. Lift off nuke from orbit. If there are paper in oil caps check that they are actually blocking DC - those are often pretty leaky by now. You'll hear it when controls remain noisy no matter how clean they are. .

31st March 2012, 10:06 PM	#4
thevalvekid diyAudio Member Join Date: Apr 2011 Location: Melbourne	I have the same little amp as my workshop amp. Single ended 6M5, it's a lovely old thing. Ronsonic is spot on. Mine was full of Ducon wax caps, be sure to get rid of those. Make double sure you replace the two caps across the power switch/volume knob. If they short, they make a heck of a mess. Use appropriate mains rated caps here. Also, keep in mind the OPT's only have a 15 ohm secondary tap.