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modded Allnic H1200 sounding thin, any ideas why?

slim

slim

pfm Member
I have bought a modified Allnic phono stage and I had high expectations but was surprised that it sounded thin. The seller told me he didn't use it much and I thought it needed more burn-in time. But now after months I think something is wrong with the upgrade. Please see the details in the following link:
https://hifiwigwam.com/megastore/product/allnic-h1200-modified-phono-stage/
The sound is clear but lack weight. Low frequencies are like they are rolled off. I am wondering what I could do to fix it? Shall I change the components again? the valves?
 
1. What valves are inside? Maybe cheapos or on their way out?
2. Is a Nordost power cord attached to it?
3. Was your sound 'thin' before you installed the Allnic?
 
Inaccurate RIAA EQ or excessively small output caps for the load impedance are about the most likely issues.

Edit: Mike got there before me on caps!
 
Arkless Electronics said:
Inaccurate RIAA EQ or excessively small output caps for the load impedance are about the most likely issues.

Edit: Mike got there before me on caps!
Click to expand...
Is the load impedance for the cartridge? If so I have the Dynavector DV-20X2 L MC which I think is quite standard to that extend.

Is RIAA something I can tweak? Thanks
 
slim said:
Is the load impedance for the cartridge? If so I have the Dynavector DV-20X2 L MC which I think is quite standard to that extend.

Is RIAA something I can tweak? Thanks
Click to expand...

No and... no. It's technical;)

It's been messed about with in ways which will not improve the sound, but, if any of the RIAA caps have been changed it could ruin the frequency response accuracy. The load impedance I was referring to is that of whatever the Allnic is feeding into.
 
Arkless Electronics said:
No and... no. It's technical;)

It's been messed about with in ways which will not improve the sound, but, if any of the RIAA caps have been changed it could ruin the frequency response accuracy. The load impedance I was referring to is that of whatever the Allnic is feeding into.
Click to expand...

Makes perfect sense, thanks. I have a nice valve power amp (Leben CS1000p) that was supposed to work better without a preamp... maybe not a good idea with the Allnic! I also use a Hugo DAC which seems very happy in the same set-up. I can try to use a cheap preamp that I have and see what happens...
 
Hi slim, This Phono was modded by Rob (Open Door) of the Wam. I've heard it in my system a couple of years ago and it sounded very fast and quite 'Naimy'. It's not really Modded as far as you might think, just had the power supply caps changed to larger Panasonics and fancy sockets and internal cabling.

I'm wondering If one or two of the replaced PSU caps has cracked a solder joint in the post.
 
And yes you can tweak the RIAA, although once you do you're on your own.

The Auri-cap interstage caps won't improve the sound as the Multicap output coupling caps are worse and are downstream. The Panasonic PSU caps are larger then the originals and have lower ESR so they should make a difference. I'm not sure but the PSU reg may have been changed too.
 
Dan K said:
And yes you can tweak the RIAA, although once you do you're on your own.

The Auri-cap interstage caps won't improve the sound as the Multicap output coupling caps are worse and are downstream. The Panasonic PSU caps are larger then the originals and have lower ESR so they should make a difference. I'm not sure but the PSU reg may have been changed too.
Click to expand...

Yes there is nothing stopping you from changing values in the RIAA network... But unless you have a load of test gear and an accurate reverse RIAA generator (I do) all you are doing is making random errors in the frequency response... hence I said no to tweaking the RIAA.

I largely disagree with the rest of your post and will leave it at that.
 
Dan K said:
Hi slim, This Phono was modded by Rob (Open Door) of the Wam. I've heard it in my system a couple of years ago and it sounded very fast and quite 'Naimy'. It's not really Modded as far as you might think, just had the power supply caps changed to larger Panasonics and fancy sockets and internal cabling.

I'm wondering If one or two of the replaced PSU caps has cracked a solder joint in the post.
Click to expand...

I bought it from Lawrence, I bet he got it from you :)

I opened it for a visual inspection (leaks, loose solder) but nothing noticeable. I assume that the 2 PSU caps are the closest to the transformer?
 
As for adjusting the RIAA, I'm completely out of my depth so I would leave it to someone who knows what they are doing.

Does someone know who could perform the mod of the Allnic 1200 that is so praised? Maybe the imbalance can be corrected at the same time...
 
I've never owned this unit. It was Rob's. I just borrowed it for a week.

TBH, I'm not entirely sure that this phono is "so praised". I found it too aggressive in my system. It did a similar thing to a Dennon 103 - not really what I like. It was replaced by the 1201 after only a couple of years. I like it as a piece of design because it's so compact, there's not much else that will compare for the same footprint.

Without removing the boards from the chassis you'll not really be able to see if the solder is intact, perhaps try gently rocking the Panasonic caps.
 
It's true that it's the modded version of the 1200 that gets lots of attention, but I haven't found anything explaining what it actually is. I have removed the boards and nothing apparent. I will look again
 
To me this unit hasn't been 'modified', it's had some component upgrades. The amp and PSU circuits have not been changed ...assuming that the red Sprague orange drop that's been put in the RIAA has the same value as the 2 parallel yellow rel caps that it replaced. It may just be that the loading is wrong for your cart.

If you have the shelf space then try a JVC AX-Z1010TN. I found the phono in that to better it
 
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