Author Topic: DIY El84 Valve amp  (Read 1829 times)

Offline Johnnie

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DIY El84 Valve amp
« on: January 11, 2018, 08:24:17 AM »
Working condition but has a slight hum so selling “voetstoots”. This beauty has potential and despite the slight hum the sound with efficient speakers is quite sublime.

DIN input(will supply a DIN-RCA cable)
ECC83 drivers
EZ81
Speaker wire out only.
Metal enclosure
Vol. Treb. Bass and Balance
Location: Klerksdorp
Price: R 2500.00
Postage: Yes (R 99.00 Postnet)
Contact: Johnnie 0826721182 or pm






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Offline Johnnie

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Re: DIY El84 Valve amp
« Reply #1 on: January 13, 2018, 03:38:54 PM »
Price drop R 1999.99!!  :coffee:

Offline King_Julian_S

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Re: DIY El84 Valve amp
« Reply #2 on: January 13, 2018, 06:15:11 PM »
... someone will get lucky here maybe ne 🤫


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Offline fredeb

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Re: DIY El84 Valve amp
« Reply #3 on: January 14, 2018, 09:16:46 PM »
Where are the output transformers ? Or is this single-ended OTL ?
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Offline El Sid

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Re: DIY El84 Valve amp
« Reply #4 on: January 14, 2018, 09:25:03 PM »
I also wondered - I think they are inside the enclosure - note the pop rivets behind the EL84s

Offline El Sid

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Re: DIY El84 Valve amp
« Reply #5 on: January 14, 2018, 10:30:33 PM »
of course I may be speaking utter  :cr@p:

Offline Johnnie

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Re: DIY El84 Valve amp
« Reply #6 on: January 15, 2018, 02:58:47 PM »
I also wondered - I think they are inside the enclosure - note the pop rivets behind the EL84s
:2thumbs:


Offline Family_Dog

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Re: DIY El84 Valve amp
« Reply #7 on: January 15, 2018, 04:43:26 PM »
This "strip and rebuild" could really make an interesting project for someone here. Powdercoat the chassis and you're well away!

People wishing to get into valves will find this an excellent project.


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Offline HBAutomation

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Re: DIY El84 Valve amp
« Reply #8 on: January 15, 2018, 04:58:34 PM »
What would the approximate specs be?
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Offline Johnnie

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DIY El84 Valve amp
« Reply #9 on: January 15, 2018, 06:39:33 PM »
I must admit I am not entirely sure my guess is Triode class AB but can also be class A maybe? El84 spec sheet attached.



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Offline Family_Dog

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Re: DIY El84 Valve amp
« Reply #10 on: January 15, 2018, 06:58:44 PM »
You should get ±4 watts out of this pretty easily. Not absolutely hi-fi sound by any means but certainly a "pleasant" sound. Input could be anything from 100mV to 500mV as it appears to use the popular Baxandall tone circuits. For the price that Johnnie's asking, you are going to find it difficult to better this. Used with high-efficiency speakers this could surprise you.


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Offline King_Julian_S

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DIY El84 Valve amp
« Reply #11 on: January 15, 2018, 08:17:10 PM »
Get this .. take help from the masters like FD, AD , AH , KM , H , K and shoo many others here ... to optimize and then join the fun with Ingvar’s horn build and as stated above you could be in for a surprise with very little cost compared to today’s prices...
« Last Edit: January 15, 2018, 08:19:43 PM by King_Julian_S »
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Offline Johnnie

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Re: DIY El84 Valve amp
« Reply #12 on: January 15, 2018, 10:47:29 PM »
Thanks KJ, I used the everything with my trusty Acousta horns with Altec 409-8E (97db SPL) drivers. Sound was always enjoyable..

I seem to be more of a function before form guy..

Offline King_Julian_S

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Re: DIY El84 Valve amp
« Reply #13 on: January 15, 2018, 10:56:02 PM »
..

Lotso sawdust and boxes there ? Any old 15” cabs around ?


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Offline Johnnie

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Re: DIY El84 Valve amp
« Reply #14 on: January 18, 2018, 04:20:19 PM »
Willing to swop for a phono amp or intergrated amp with pre-in main-out that has phono. :coffee: