I use it as a headphone amp and I can hear clearly that the vocal is NOT in the middle, it's more to the right, together with all sounds.
so I guess the bias between two tubes is not equal.
I use Stereo Potentiometer.
I hope the new version will fix that.
Cal
so I guess the bias between two tubes is not equal.
I use Stereo Potentiometer.
I hope the new version will fix that.
Cal
List of parts
Anyone can report the list of materials that comes in the kit? Which site is all the connectors, in Mouser?
Beftus, how much the cost of your modification? It would be valid to have placed 470uF instead of 220uF?
The pcb can be easily modified for a better distribution? The new model on eBay is not so practical.
Anyone can report the list of materials that comes in the kit? Which site is all the connectors, in Mouser?
Beftus, how much the cost of your modification? It would be valid to have placed 470uF instead of 220uF?
The pcb can be easily modified for a better distribution? The new model on eBay is not so practical.
just got mine
mine just arrived in the mail, its the new improved version K272A with the 2 power supplies needed.
I'm going to replace the resistors, caps and op amp with better parts, and perhaps use something like this:
Low Voltage Adaptor Kit - Jaycar Electronics
with a walwart replace the batteries..
I'll just be using mine as a line level preamp.. I'll stick in a stereo potentiometer and a 3 input selector switch as well.
mine just arrived in the mail, its the new improved version K272A with the 2 power supplies needed.
I'm going to replace the resistors, caps and op amp with better parts, and perhaps use something like this:
Low Voltage Adaptor Kit - Jaycar Electronics
with a walwart replace the batteries..
I'll just be using mine as a line level preamp.. I'll stick in a stereo potentiometer and a 3 input selector switch as well.
Hi Everyone
I am a newbie here, i built this and found that if you want to use stereo pot , the tube need to be match so that they have the same gain.
Regards
OPA623AP
I used the burr-brown OPA623AP, on the main board, it dropped right in! I have not done the phono section. I don't know if the one you want to use will work. As I said, I changed all the caps except the silver mica, those were made by siemans and are very good. Here's some pics.
Peter C.
I used the burr-brown OPA623AP, on the main board, it dropped right in! I have not done the phono section. I don't know if the one you want to use will work. As I said, I changed all the caps except the silver mica, those were made by siemans and are very good. Here's some pics.
Peter C.
Attachments
This kit make me have an ideas in DIY a new headphone amp. , but the kit shown that the filament is connect in series. In the case the filament is driving in 1.25*2 that will be 2.5Volt. < that's the place that i does not understand, filament connect in series are unusual ? And as the kit said the op amp gain is equal to the R7 / R3 which is 1Meg /1Meg = 1 but why this resistor will be that large? what's the reason?
I've modded mine a bit by putting it in a larger box and adding an Alps 50k stereo pot for volume control. I also added an on off switch and run 2 batteries in parallel.
As I have no headphone socket on my main amp this sits between DAC and amp.
I have added a pass through so that when the headphone amp is off the signal is routed to my main amp and when on the pass through is open cct.
As I have no headphone socket on my main amp this sits between DAC and amp.
I have added a pass through so that when the headphone amp is off the signal is routed to my main amp and when on the pass through is open cct.
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