Allnic H3000 naked z-foil vishay tweak

This is for those Allnic owners that are handy with a soldering iron or know someone that is. I've owned the H3000 for about a year before I decided to try this and I'm glad I did. I bought some 68k naked z-foil resistors. I bypassed the input resistor switch and soldered them straight to the input block. This of course will mean you can not change the resistance without soldering in a different resistor but I found no need to do so in my setup. I also have a friend that tried it on his unit with good results as well. On the Allnic you can still adjust the loading somewhat by adjusting the step up transformers.

This results in a sound that is more pure. It does not change the tonality that I noticed. At least in my system and that of my friends there was no down side short of less loading options.

H3000.jpg
 
Last edited by a moderator:
This is for those Allnic owners that are handy with a soldering iron or know someone that is. I've owned the H3000 for about a year before I decided to try this and I'm glad I did. I bought some 68k naked z-foil resistors. I bypassed the input resistor switch and soldered them straight to the input block. This of course will mean you can not change the resistance without soldering in a different resistor but I found no need to do so in my setup. I also have a friend that tried it on his unit with good results as well. On the Allnic you can still adjust the loading somewhat by adjusting the step up transformers.

This results in a sound that is more pure. It does not change the tonality that I noticed. At least in my system and that of my friends there was no down side short of less loading options.

I have the small brother, the Allnic H-1500. In this phono, one have to change the resistor on the board, no external switch. I wonder if the fact of solder the resistor is responsible of the increase of the sound purity in the H-3000 ?
In other world: Have you tried to change the standard resistors by z-foil ones without soldering ?
 
Last edited:
Hi Benito,

In the H3000 there is no way to change resitors without desoldering and resoldering. Don't know what the inside of the H1500 looks like but I don't think you can swap resistors without soldering. Some phono stages are designed that way though.

Different solders do sound different and can contribute to the sound chartacter. What I heard when I swapped in the z-foil resistors I could not atribute to the sound of different solder alone. Z-foils lower the noise floor. Not aware of any solder that does the same thing.
 
Do you have any pictures or instructions of the H3000 Mod?

Sorry I don't have pictures. I no longer have the Allnic. I remember it being fairly simple to do. If you follow where the leads from the switch go, that is where the you would solder in the resistor instead. You would need to desolder the switch and place the resistor across the same points. If I remember correctly the ground side of the switch is a thick copper wire that runs the length of the chassis. A lot of stuff is grounded to that wire. One side of the resistor goes there and the other side goes to where the positive side of the switch goes. You need one resistor per channel.

This will most likely void any warranty that you have left. So I would not do it unless you are confident in your skills. The biggest danger is dripping solder on something you did not mean to, which can short something out if you do not notice it and fix it first.
 
Hi Benito,

In the H3000 there is no way to change resitors without desoldering and resoldering. Don't know what the inside of the H1500 looks like but I don't think you can swap resistors without soldering. Some phono stages are designed that way though.

Different solders do sound different and can contribute to the sound chartacter. What I heard when I swapped in the z-foil resistors I could not atribute to the sound of different solder alone. Z-foils lower the noise floor. Not aware of any solder that does the same thing.

No soldering in the H-1500. If you look to the large picture (click on picture) on the right between the MC transformers and the middle pair of 417A tubes, you can see that the resistors R1 and R2 are soldered on the board. A good tweak to try, I will do it soon.
 
If you wanted 47k on that input, you would put in a 47k resistor, correct?
With a Koetsu Blue Lace with 0,4 mV output, I guess that you set the MC transformers to X20 so the impedance is 47k/20^2= 117 ohm. What I read on the net that the recommended Load is between 80-1,000 ohms, so you should be at the lower range. Cartridge loading is not an exact science, it depends on the whole system, so a try approach is recommended.
 
Some vintage MMs prefer to be loaded up to100k. In fact, I had a NIB Grace F-9 that supplied its specs into 100K. Zesto is a manufacturer that offers a higher switchable option for MM, 68K as I recall, in its Tessera.

My H3000 was specially made (for Albert Porter, from whom I bought it) with switchable 75K and 100K options.
 
  • Like
Reactions: advanced101
The Z-foils are the best audio resistor by far. You can almost use as many as you want with no downside, although you need to be careful of their voltage rating in tube circuits. Better transparency and presence with just enough tonal color and very low noise. I have used hundreds of these in various modifications, including a phono stage with 70 of them in signal paths. Last time I looked, these laser-etched babies only came in .1% tolerance values -how's that for a resistor spec? Their thermal noise is 1/10th the value of a typical metal film resistor. Of course they cost a lot more too which is why you don't find them in most audio products.

You can buy these direct from Texas Components on their website - no minimum order quantity.
 
Last edited:
Changed last night the loading resistor on my H1500, that works very well: the sound is more pure without changing the orher characteristics of the phono. Great and simple tweak on this model since no soldering required.
 
Here is a photo of the impedance switch (Box with 8 resistors). Looking inside now, the mod will be easy. I also see other opportunities to simplify the signal path, albeit reducing the flexibility of the unit. I don't plan on upgrading my phonostage for a few years, I might take this opportunity to do a few things.
 

Attachments

  • IMG_5261.jpg
    IMG_5261.jpg
    704.9 KB · Views: 43
  • Like
Reactions: matakana
Here is a photo of the impedance switch (Box with 8 resistors). Looking inside now, the mod will be easy. I also see other opportunities to simplify the signal path, albeit reducing the flexibility of the unit. I don't plan on upgrading my phonostage for a few years, I might take this opportunity to do a few things.

I have the same phono and just use the MM INPUT, I have been advised that this input 47kohm does not have a resistor in place as its direct, is this not the case? if so Iam keen to get a zfoil 47kohm one and solder in place.
 
I believe all the inputs go through the resistor switch. If you look at my picture, there is a header (black box) to the right that all the inputs connect into and the output is paralleled with the resistor switch.
 
I believe all the inputs go through the resistor switch. If you look at my picture, there is a header (black box) to the right that all the inputs connect into and the output is paralleled with the resistor switch.
Yes it does ,so it looks like there is a 47kohm for the left and right channel which corresponds to the other resistors that are left for the other values being 10,20,33kohm x 2 So the guys that are using their SUT are actually going through a stock 47kohm resistor too?
 
Here is a photo of the impedance switch (Box with 8 resistors). Looking inside now, the mod will be easy. I also see other opportunities to simplify the signal path, albeit reducing the flexibility of the unit. I don't plan on upgrading my phonostage for a few years, I might take this opportunity to do a few things.
Hello advanced101
Did you complete a zfoil resistor upgrade yet?
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing