Harversonic Stereo amplifier - UK Vintage Radio Repair and Restoration Discussion Forum

Goodizzy · 30th Nov 2019, 3:49 pm

Morning from across the pond,

I came upon this on my never-ending quest for early UK valve/transistor amps. I searched and found a few other posts regarding Haverson surplus, but they were all valve related. And practically nothing on the world wide web.

Anyone ever own or hear one of these Haversonic amplifiers?

Goldie99 · 30th Nov 2019, 4:06 pm

Try page 91 of the following pdf file - it's a 1976 ad from Harverson Surplus, that suggests it may be the 'Supersound 10+10 Stereo Amplifier kit'.

https://www.americanradiohistory.com...PW-1976-10.pdf

Alan

Edit - spelling corrected

dazzlevision · 30th Nov 2019, 4:11 pm

It's actually HaRversonic, not Haversonic.

Goodizzy · 30th Nov 2019, 4:23 pm

Apologies! And thanks, that appears to be it!

qualityten · 2nd Dec 2019, 11:15 am

And, I'm sorry to say that it doesn't look to be anything special.

Mooly · 5th Dec 2019, 4:54 pm

Well I managed to persuade my parents to buy me the 10+10 when I was a youngster... and just look what that led to.

I eventually managed to get one channel working and then some time later the second channel. It was a surprisingly capable performer and stood comparison sonically with my parents B&O at the time.

The circuit was a classic five transistor quasi complementary with AD149 outputs, all in a neat folded metal chassis with wooden side panels and I think a black metal top. A smart front panel was also included. 2N3702/4 made up the other semiconductors.

phykell · 9th Dec 2019, 6:55 pm

There's one on the UK eBay site at the moment:

eBay item number: 114003765126

The internals and the construction are interesting including the bridge rectifier being soldered directly to the transformer terminals. 2N3614 Germanium power transistors...

I've got a Harverson valve amplifier - it's a variant of the classic Mullard 5-10.

Mooly · 9th Dec 2019, 8:51 pm

Wow, now that really does bring back memories. Mine was internally similar although the bridge in mine was a selenium type (although I didn't know that is what type it was at the time) and bolted to the chassis. I wonder if this one has had it replaced.

The speaker coupling caps were just 470uF and the 'treble' control was in reality just a high cut filter, no boost and cut despite the panel markings. Can't remember how the bass control was wired now tbh.

That mains switch looks a bit scary now. The outputs in mine were were AD149's and I seem to recall the single rail supply was around 28 volts DC.

Edit... I wonder if that one was supplied ready built as it looks very neatly constructed in all respects and it also has a badge on the rear panel.

30th Nov 2019, 3:49 pm	#1
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Harversonic Stereo amplifier Morning from across the pond, I came upon this on my never-ending quest for early UK valve/transistor amps. I searched and found a few other posts regarding Haverson surplus, but they were all valve related. And practically nothing on the world wide web. Anyone ever own or hear one of these Haversonic amplifiers?

30th Nov 2019, 4:06 pm	#2
Goldie99 Heptode Join Date: Jul 2014 Location: Boston, Lincolnshire, UK. Posts: 995	Re: Harversonic Stereo amplifier Try page 91 of the following pdf file - it's a 1976 ad from Harverson Surplus, that suggests it may be the 'Supersound 10+10 Stereo Amplifier kit'. https://www.americanradiohistory.com...PW-1976-10.pdf Alan Edit - spelling corrected Last edited by Goldie99; 30th Nov 2019 at 4:13 pm. Reason: Spelling

30th Nov 2019, 4:11 pm	#3
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,608	Re: Harversonic Stereo amplifier It's actually HaRversonic, not Haversonic.

30th Nov 2019, 4:23 pm	#4
Goodizzy Pentode Join Date: Jan 2016 Location: Lynchburg, Central Virginia, USA. Posts: 137	Re: Harversonic Stereo amplifier Apologies! And thanks, that appears to be it!

2nd Dec 2019, 11:15 am	#5
qualityten Octode Join Date: Feb 2009 Location: Wallasey, UK. Posts: 1,310	Re: Harversonic Stereo amplifier And, I'm sorry to say that it doesn't look to be anything special.

5th Dec 2019, 4:54 pm	#6
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Harversonic Stereo amplifier Well I managed to persuade my parents to buy me the 10+10 when I was a youngster... and just look what that led to. I eventually managed to get one channel working and then some time later the second channel. It was a surprisingly capable performer and stood comparison sonically with my parents B&O at the time. The circuit was a classic five transistor quasi complementary with AD149 outputs, all in a neat folded metal chassis with wooden side panels and I think a black metal top. A smart front panel was also included. 2N3702/4 made up the other semiconductors.

9th Dec 2019, 6:55 pm	#7
phykell Tetrode Join Date: Jun 2011 Location: Liverpool, Merseyside, UK. Posts: 54	Re: Harversonic Stereo amplifier There's one on the UK eBay site at the moment: eBay item number: 114003765126 The internals and the construction are interesting including the bridge rectifier being soldered directly to the transformer terminals. 2N3614 Germanium power transistors... I've got a Harverson valve amplifier - it's a variant of the classic Mullard 5-10.

9th Dec 2019, 8:51 pm	#8
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Harversonic Stereo amplifier Wow, now that really does bring back memories. Mine was internally similar although the bridge in mine was a selenium type (although I didn't know that is what type it was at the time) and bolted to the chassis. I wonder if this one has had it replaced. The speaker coupling caps were just 470uF and the 'treble' control was in reality just a high cut filter, no boost and cut despite the panel markings. Can't remember how the bass control was wired now tbh. That mains switch looks a bit scary now. The outputs in mine were were AD149's and I seem to recall the single rail supply was around 28 volts DC. Edit... I wonder if that one was supplied ready built as it looks very neatly constructed in all respects and it also has a badge on the rear panel.