Thetiminator

Don't change it....upgrade it!

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Super Wammer

So.......I got into headphones for the first time a few months ago and ended up settling with the excellent EAR HP4 amp which is the best headamp I had heard (by quite a margin). Of course never being happy with my lot I got itchy feet after a few weeks wondering if the amp could be improved in any way.

So I started a thread for advice and was pointed in the direction of our member Juancho (David). After a quick PM'ing session I sent it over for him to take a look at. David got back to me after a couple of days saying he had a look at it and that there was definitely things that could be done to improve it. He gave me a breakdown of what he could do (you'd be surprised at some of the crap parts that are in a £5k headphone amp), a rough idea of cost of all of the options and rough timescales. I gave him the go ahead to go to town on it basically. David advised that the best 6SL7's tend to be the tall bottle variety rather than the shorts that were standard fit to the amp. He told me that he could fit some tasty tall bottles but I'd have to use it with the case off. Again, I gave him the go ahead to knock himself out and I'd get something sorted for the case.

About a week later I got the call to say it was ready and back it came. In short.....WOW! I thought the amp was good before, but now the SQ was on a totally different level. Gone was a huge amount of grain that I didn't realise that was there, the bass had gone through the floor and the treble now sparkled like I had never heard before. Seriously, the amp was twice as good as it was before, in fact I'd say it is the most impressive piece of hifi and the best sound I have ever heard.

The cost of this magic was a pitful (for the gains in SQ) c.£600 plus valves. David had recommended NOS RCA's for the front pair (input stage?) and Sophia Electric NOS's for the rear pair (driver stage?), the SE's are the tall bottles but said the SQ was stunning with them in and worth keeping the case off for. Over the next few days I had a play between the SE's, the RCA's and the standard Sovteks and it turned out that David had the combination bang on.....I've never rolled tubes before I was surprised at the difference between makes of valves, the Sovteks being awful sounding (bright and nasty) compared to the others.

A quick note to David if you're there - I ordered another pair of the SE's out of interest and ran it the other pair in the front, interestingly it sounded rubbish (horribly bright) with two pairs of the SE's.

So, to the casework problem....I trotted off to my local metal fabricators and had a lurvly stainless steel case made up with a hole to fit the valves and a dinky, detachable and ventilated cover to cover the tops of the taller tubes. This cost £120 all in.

So like I say, for £700 I have an amp that sounds at least twice as good as it did and is without a doubt the best sounding piece of hifi I have ever heard. So before you think of changing your equipment and getting hammered both ways on the deal, maybe give Juancho a call?

Finally, just a thanks to David who is a total gent and did everything as promised from start to finish, top bloke!

Here's a list of the work:

1. Capacitors

1. The amp used fairly basic industrial style capacitors - replaced all power supply electrolytic capacitors with good quality Dubiliers and Nichicons (7 in total)

2. Upgraded all key capacitors in the signal path using Mundorf ZN's and Musicaps in coupling positions and Elna Silmics in cathode bypass positions (6 in total)

2. Power Supply

1. Power supply improved by installing a 15 Henry choke in place of a dropper resistor and by replacing the standard diodes with Schottkies.

2. Converted the power supply to a pseudo mono supply using separate chokes and filter caps for each channel - allows the separate channels to function in virtual independence with their separate choke filters and reservoir caps

3. Valve Sockets

The standard nickel ones replaced with gold plated ones x 4

4. Valves (both sent to choose)

1. Black plate RCA 6SL7s for £105.

2. Tung Sol reissues for £75.

6. Key Resistors

Could not identify the resistors used, assumed they are metal oxide - changed these for quality Kiwame carbon film resistors. Replaced 10 resistors.

Some pics.......

1st photo is the stock internals and then upgraded internals and new case from there on in.....

http://s1290.photobucket.com/user/timcdoran/library/EAR%20HP4

Ain't it pretty? ;)

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Super Wammer

Photos:

1st photo is the stock internals and then upgraded internals and new case from there on in.....

http://s1290.photobucket.com/user/timcdoran/library/EAR%20HP4

Ain't it pretty? ;)

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Attachment links aren't working. Best to use Photobucket or similar.

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Super Wammer

If you click the attachment link the pic appears?....does at my end...

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Guest MJ.
If you click the attachment link the pic appears?....does at my end...

Nup, not here :nup:

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nothing here from the attachments...........

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Super Wammer

Photos added via photobucket.......

1st photo is the stock internals and then upgraded internals and new case from there on in.....

http://s1290.photobucket.com/user/timcdoran/library/EAR%20HP4

Ain't it pretty? ;)

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Gone was a huge amount of grain that I didn't realise that was there

If you didn't know it was there how do you know it's gone?

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Super Wammer

Not sure if the question was a form of joke but....

I didn't realise how much grain was there until it was gone and the sound was much more natural and pure.

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Photos added via photobucket.......

1st photo is the stock internals and then upgraded internals and new case from there on in.....

http://s1290.photobucket.com/user/timcdoran/library/EAR%20HP4

Ain't it pretty? ;)

It is - they've done a nice job of case.

5_zpsawivt4wk.jpeg

6_zpsrbg3fadr.jpeg

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Super Wammer

Indeed, amazing job for £120. I'm really happy with it and it fits perfectly too, all the screw holes etc. match spot on. Much better than the original casework......

[ATTACH]14818[/ATTACH]

61776411_EAR1.jpg.dec93fee33381750e7944b

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Super Dealer

Finally grabbed a few minutes to look at the finished casework! It really does look great, looks to match the sound! There's a bit of irony in these mods and upgrades. The mods to the power supply were inspired by a Tim De Pavaricini design he used in a power amp (which I use in my 300b power amp). Like so much in valve amplification, I don't know if he originated that design, or whether its origins were much earlier, but that was certainly the inspiration for my power supply upgrades.

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Lovely. An approach I totally agree with!! It seems to be a big recurring theme that the power supply side of things can usually be improved..

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