Allison 6 Refurb.

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Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Sun Dec 10, 2017 2:17 pm

4.7 ohm resistor now in place instead of 10 ohm. Much better overall. I've also added a Vishay MKP1837 / 0,01uF cap in parallel with the 3.3uF which has cleaned things up a bit. Naturally being unstuffed and unlined the cabinet is now singing along a bit, so steel lining is next. Once the basics are sorted will then think about upgrading the rather basic capacitor to something better, probably a Jantzen Superior Z-cap.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Sun Dec 10, 2017 8:05 pm

The Vishay has come out. It adds an artificial 'detail' sheen to the top end. Increasing the resistor to 6.8 ohms retained the artificiality of the treble. However, removing the Vishay cap restored a much more natural top end. This little experiment suggests that capacitor quality is indeed important. Overall, with the 6.8 ohm in the sound is pretty balanced but lacking air and transparency which may well be down to the budget Audiophiler cap. A Jantzen Superior Z-Cap may well be the way forward unless a pair of those Russian jobs pop up.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

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Dr Bunsen Honeydew
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Re: Allison 6 Refurb.

Unread post by Dr Bunsen Honeydew » Sun Dec 10, 2017 8:35 pm


Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Sun Dec 10, 2017 9:06 pm

Cheers Doc. That's one less pair available.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Sun Dec 10, 2017 10:15 pm

Obviously early days yet and the new listening room is still a complete tip after the move, but these semi-omnis are keepers. The new Russian caps should improve things further as will the steel. A good sign is that I keep getting distracted by what's playing (currently The Cinematic Orchestra -
The Crimson Wing) instead of concentrating on what I'm supposed to be doing.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

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karatestu
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Re: Allison 6 Refurb.

Unread post by karatestu » Mon Dec 11, 2017 1:41 pm

Yes, the Russian PIO caps are very very good. I got 2 pairs :grin:

So, the semi Omni approach is a winner for you the Simon ? Had you heard any before this ?
Naim, Linn & Harbeth fanboy

Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Mon Dec 11, 2017 2:44 pm

Yes, I think it's going to work well for me. With respect to omnis in general, not a huge amount of experience Stu. I've heard omni type speakers at shows, the best being a large pair of Zeta Zero Orbitals. A friend also had a pair of Shahinians which were pretty good, although for some reason he PXed them for a pair of Audiovectors. But then he did have a Naim/Linn system.

My room isn't properly set up yet by any means with junk lying everywhere. I cannot quite pin down what the difference is. For some reason I was thinking the soundstage might be taller, but there's still a lot of setting up to do. I suppose the main difference is that the music is just 'there' as opposed to being thrust at you. Unfortunately one of my bass drivers has developed a buzz with loud low frequencies. I think I might have damaged it with a previous OB experiment. So another 8 inch driver and some Bison Kit will be on the way shortly. If I then diagnose the problem and it's fixable at least I have a spare. I need to get those cabs steel lined too.

I also as of yesterday have a Raspberry Pi for the music system. I simply installed Volumio, attached a USB hard disk, my AQ Dragonfly Red USB dac and once set up with the home network, operate it wirelessly from my laptop. It cost £44 and a bit.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

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karatestu
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Re: Allison 6 Refurb.

Unread post by karatestu » Mon Dec 11, 2017 3:00 pm

Simon Hickie wrote:
Mon Dec 11, 2017 2:44 pm

My room isn't properly set up yet by any means with junk lying everywhere.
That's what my workroom looks like all the time :lol:

Glad you are liking it. As for the soundstage - I am not sure what I expected but am completely happy. :grin:

You may need to play about with positioning :think:
Naim, Linn & Harbeth fanboy

Simon Hickie
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Re: Allison 6 Refurb.

Unread post by Simon Hickie » Tue Dec 12, 2017 1:25 pm

The Russian caps have arrived. They are a bit big! I think that taking the tweeter components outside the box is probably now wise, especially if I steel line the cabs. So time to get the drill out again to add a couple of terminals.
“The reasonable man adapts himself to the world: the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.” George Bernard Shaw.

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Dr Bunsen Honeydew
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Re: Allison 6 Refurb.

Unread post by Dr Bunsen Honeydew » Tue Dec 12, 2017 1:34 pm

No need they sit in the box no problem, I just glue them in with Bison so I can get them out again if needed. Paper in oil caps should be big, if they are small then doubt them.

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