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Old 25th September 2019, 05:23 PM
YummyFuzz YummyFuzz is offline
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Location: Perth, Australia
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Default KEL84 from the recycling centre

Hello,

I was fortunate enough today to pick up a KEL84 from the rubbish/recycling centre near my work. It is missing the chrome volume knob, and has no tubes, it appears to only have the wiring done for the CD input, of which the black wire is broken, the wiring is messy, and the soldering is blobby in places, but no components seem wobbly, or joints dry. It was sitting in the bottom of a trolley of hi-fi equipment, yet to be put on the shelf and priced for sale. The tube sockets on top and the sheer weight of the thing suggested some value, so I took it up to the counter to inquire on the price of it. "10 dollars" (AUD).

My usual hobby is building, repairing, and modifying guitar pedals of different sorts, with a recent interest to move into working on the several tube guitar amplifiers I have, and though not a guitar amp, this for the price seems like a good opportunity to get started with valves.

I've spent the last several hours reading what information is to be found on the KEL84 to see what I've gotten myself into, and have joined this forum to see if you can help or advise me how to get some build instructions (for purchase?) for the KEL84 as I think I'd like to back out and redo some of this wiring. Next I guess would be getting a matched pair of ECF80, and a quad of EL84 off eBay, though how discerning I need to be on this I don't know, and then run through the test and measure sections of this forum.


I do have a local Hi-Fi amplifier repair person who I'm sure I could pay to source the parts and make the repairs, but where's the fun in that.

I'm new to this forum, or any kind of forum for that matter, so please be kind.

I don't even have a set of speakers (advice for later).
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Last edited by YummyFuzz; 25th September 2019 at 05:27 PM. Reason: A word and rephrasing.
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  #2  
Old 25th September 2019, 05:41 PM
bob orbell bob orbell is offline
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Join Date: Nov 2009
Location: kettering northants.
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Default Re: KEL84 from the recycling centre

10 dollars, you did very well, the forum Administrator Matthew Snell is the person to ask for the instruction papers, go to the very bottom of the page to CONTACT US and give Matthew an email. Valves from ebay will be fine on this amplifier, 4 matched EL84's and 2 ECF80, matched if you wish, but not really necessary. Also lots of help on this forum, and just to add, do not run the amplifier without a speaker load, speakers or a two load resistors. Bob
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  #3  
Old 26th September 2019, 09:56 AM
John Caswell John Caswell is offline
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Join Date: Dec 2005
Location: Wokingham, Berkshire
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Default Re: KEL84 from the recycling centre

Hi
Nicely done, looking at the PCB it seems to be the Mk1, the only difference being the PCB between 1&2 and also the provision of relay input switching, which you can add if you wish at a later date.
As Bob says matched EL84s are the best way to go and if you can get them E80CF as opposed to ECF 80 as they tend to be closer toleranced than the ECF80, see my comments and FAQ. There is plenty of help here available so if you or your repairer gets stuck just ask.

John
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Old 26th September 2019, 10:09 AM
Richard Richard is offline
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Join Date: Dec 2005
Location: Notts
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Default Re: KEL84 from the recycling centre

Yes, hello and welcome that was a great deal!

I thought I did well getting a pair of Quad II monoblocs from a junk shop window in 1977 for 8 (about 50 today) when they were out of fashion!

If you've not already got them send me a message with your email address and I'll send the info you need
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  #5  
Old 27th September 2019, 06:47 AM
YummyFuzz YummyFuzz is offline
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Join Date: Sep 2019
Location: Perth, Australia
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Default Re: KEL84 from the recycling centre

Thank you Bob and Matthew. I now have the build instructions, and the valves on order (2 x ECF80 6BL8 EI Yugoslavia - NOS matched pair (Philips construction), and a matched quad of EHX EL84's). I'll also get some cheap 8ohm speakers to test with.

I spent last night removing all the wiring off the 6-way selector switch, volume pot, and the audio connectors at the back which was all single core copper wire that would have been unwieldy to work with. My feeling is that this was an abandoned kit, and may never have worked for the previous owner as some of the audio cables seemed to essentially crimped to breaking in the act of removing the shielding.

I want to get the entire PCB out but is is being held in mainly by the choke and mains transformer wiring.
What is the opinion on having a series of either plug or screw connectors between most (choke and transformers) of the onboard and offboard wiring to allow easy removal of the PCB?

I'll clean the board and reflow the solder as well as suction up some of the excess. I'll be getting some new wire, and a 100ka volume pot as well while waiting for the valves.

A part I will probably be looking for in future is a replacement chrome volume knob, and I notice that chroming the transformer covers is popular, but I was thinking just black paint.
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  #6  
Old 27th September 2019, 07:43 AM
YummyFuzz YummyFuzz is offline
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Location: Perth, Australia
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Default Re: KEL84 from the recycling centre

Those Quad II monoblocs look amazing!
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