Massdrop x Eddie Current ZDT Jr. (Official Thread)

I think they have laminated it to make it easier to work with and for safety as the material is thin metal and could give you a nasty paper cut!

 

Thank you all for the help. I successfully shield my amp. It was quite loud before and now almost dead silence. Here is the pictures.

https://www.reddit.com/r/headphones...urce=share&utm_medium=ios_app&utm_name=iossmf

 

Hey guys, I have some very low volume balance issue. When starting from 0 volume the right seems to be louder then left and even out around 10%. I want to replace the volume pot. I notice there is a post here that replaced with 100k ALPS JAPAN. I bought that but when taking the old one out, it labeled only at 20K. I assumed I can't use the 100K ALPS and need to buy another one that match the 20K?

 

If the original is a 20k pot, you could strap a 25k resistor across it in parallel to bring it down to 20k. You would need one for each side.

 

Hi, thank you for your response. so if i order 2 25k resistors. are those 1/2watt? so do i solder that inline into the input or output?

 

The dual ganged pot has three lugs for each gang. So they would go across the two outer lugs. One for each gang.
I would think 1/4watt would work, but you could use 1/2watt if you really wanted.

 

So based on this picture one will connect between ground and input1, and one will connect ground and imput2. linking those two pin together of each gang.

https://tangentsoft.net/audio/bitmaps/annotated-rk27.jpg

 

Correct.

 

That was my post from awhile back regarding the 100k ALPS pot.

What would be the issue with just using the straight 100k pot in place without stepping it down to 20k?

I've had it in place for awhile now and it does not seem to have had any noticeable negative effect, besides fixing the malfunctioning original!

 

Thanks for the reply. Yes I follow your post to how on replace the pod =). This is what I am unsure of the negative effect. While I was told that I am not suppose to go above 15-20% of the original ohm. Still really to all this so not quite sure.

 

I think you'll be OK with the 100k pot, as long as it has an audio taper. As I understand it, a different resistance value will just shift the equivalent volume setting to a different place on "the clock". But you should still have a usable range with an audio taper pot. I replaced the pot on my MCTH with one of a different resistance (don't remember the exact values) and it worked fine.

Basically, you won't break the amp. The volume setting will just be in a different place for the same loudness.

 

Thanks all for helping again. I was able to use the 100k ALPS and it works great.it solved my low volume balance issue.

 

Hey guys, curious what are common failure modes of this amp? Old buddy says his is busted and out of warranty.

 

It depends on the signs of damage. What's wrong with him?

 

Good point. Gotta find out!

 

OK I am told it is simply not powering up. Swap tubes no change.

 

Start with the obvious first, did you check the fuse to see if it is blown?

Ofcourse then the next question to ask is, why did it blow.

 

Got it in my hands now.

First blush all seemed well and I saw nothing wrong, powered up just fine and everything worked even when left on for about an hour. Powered it down and left it off for the night, in the morning it's not powering on. Back tubes are lit, front tubes are not, no power to LED, no sound output.

 

This is a simple malfunction. The chip for stabilizing the heating of the first tubes became capricious.
The chip is called KP1158EH6. It is located in the middle of the board. It can be replaced with the BA60BC0T

https://ru.mouser.com/ProductDetail...=sGAEpiMZZMt1hubY80/s8DfNvvmSd5PnKnopMcakSvw=