the selection of the pot impedance is an interesting issue Here there are opamps buffering the inputs, driving the pot and an opamp output stage
I wonder what kind of difference would cause using a 10k pot and a 100k pot on both measurements and sound
Maybe a 10k pot put will increase the contribute of the input buffers ? and viceversa a 100k pot ?
If possible i would also try to bypass the input buffers with a very low Z pot Straight wire without gain
I wonder what kind of difference would cause using a 10k pot and a 100k pot on both measurements and sound
Maybe a 10k pot put will increase the contribute of the input buffers ? and viceversa a 100k pot ?
If possible i would also try to bypass the input buffers with a very low Z pot Straight wire without gain
These days 10k pots are generally preferred due to lower inherent Johnson noise, less chance of EMI pickup at the lower impedance too. Nearly all opamps are happy driving 10k loads too, so it makes sense. With high signal levels 100k will be fine though, its only 20nV/√Hz for 100k pot mid-range (6nV for 10k).
Hi,
I've been here for quite some time. I don't recognize your username for other forums I'm on? HC?
Update, this past week the 6010D Clone preamp I have upgraded has really opened up and sounding really nice. I can't wait to put the TKD pot in. I remembered the other day I have a few Noble pots from some GAS and SUMO preamps, so I should around 4 of them. I will have to pull the preamps out of the storage room and see what the values are.
OK, latest update. I pulled the Alps VC and found out its a Quad type VC. So I will not be able to use any of my VC pots that I have on hand. So I will have to wait until I have the extra $$$ for a GoldPoint Quad pot to use with this preamp. Also I did confirm after I pulled the Alps out it was definitely off between left and right channels, this was the reason for one channel being louder than the other.
The Alps is a 100K pot but I was thinking of going with either a 25K or 50K pot when I replace this one. Just wonder if this will need any mods to the IC's or can I get away with a 25K (First Choice) pot in in place of the 100K without causing any issues? The Pot is definitely after the First Buffer Stage in this unit since I traced it out to make sure. So from what I can see and measure so far, the preamp goes First Buffer > Gain Stage > Output Buffer Stage.
The new GoldPoint pot should really raise the SQ level by a couple of levels compared to that RK168 series Alps Motorized pot. The Gold Point should barely fit in this Clone preamp after looking at the data at the Gold Point website.
Up to this point the MBL 6010D Clone with add upgrades that I did to has really made this pretty good sounding preamp way better to the point where its hard for me to stop listening to music into late of night! 🙂 If it wasn't for that balance issue on the VC control I probably would just stop at this point.
The Alps is a 100K pot but I was thinking of going with either a 25K or 50K pot when I replace this one. Just wonder if this will need any mods to the IC's or can I get away with a 25K (First Choice) pot in in place of the 100K without causing any issues? The Pot is definitely after the First Buffer Stage in this unit since I traced it out to make sure. So from what I can see and measure so far, the preamp goes First Buffer > Gain Stage > Output Buffer Stage.
The new GoldPoint pot should really raise the SQ level by a couple of levels compared to that RK168 series Alps Motorized pot. The Gold Point should barely fit in this Clone preamp after looking at the data at the Gold Point website.
Up to this point the MBL 6010D Clone with add upgrades that I did to has really made this pretty good sounding preamp way better to the point where its hard for me to stop listening to music into late of night! 🙂 If it wasn't for that balance issue on the VC control I probably would just stop at this point.
@Drummerboy2 Can you post a pic of your board. About to buy a kit, would like to know the one you got. The gold points are very nice, pricey, as much as the ad797.
if the resistors are good even a stepped series attenuator can sound very very good and very balanced
I had one made with a decent mechanism and Holco resistors By far the best pot i have ever had
It must be somewhere in the mess now
Imho it is about the contact efficiency at wiper level
I had one made with a decent mechanism and Holco resistors By far the best pot i have ever had
It must be somewhere in the mess now
Imho it is about the contact efficiency at wiper level
Replaced the Pot in my Clone and it was the pot that had a lower channel. I'm still saving to get the Goldpoint quad pot.
Today I finally put the preamp portion of the all out EAR 834P in my Clone enclosure that I bought a while back. I did this to get an idea of how this all out build will sound. I was really surprise Upon power up and after 20 mins of warm up, this build is way better than the one I fully tweaked out that I have been using.
This build has both the upgraded power supply and preamp board with the Jensen Copper Foil PIO caps. The sound stage is bigger, wider, and deeper. It has that gorgeous mids that the Jensen caps are known for. This reminds me a lot of the BAT VK-P10 phono preamp that I heard and loved so much years ago. Vocals, strings and horns are just so nice. The other Clone that I had been using was really nice but sound thing at times, this new all out build is totally different with more natural presentation.
So now that I got a good idea of what this preamp is going to sound like, I can now move on to the building of the enclosure for this all out build. I was going to mount the Antek Transformer inside but I will put it in a separate enclosure and run an Umbilical Cord to the main preamp enclosure. I will mount the power supply pcb inside the main preamp enclosure as well.
Still thinking of how I will layout the front panel, I will check out some gear and see what I will do.
This build has both the upgraded power supply and preamp board with the Jensen Copper Foil PIO caps. The sound stage is bigger, wider, and deeper. It has that gorgeous mids that the Jensen caps are known for. This reminds me a lot of the BAT VK-P10 phono preamp that I heard and loved so much years ago. Vocals, strings and horns are just so nice. The other Clone that I had been using was really nice but sound thing at times, this new all out build is totally different with more natural presentation.
So now that I got a good idea of what this preamp is going to sound like, I can now move on to the building of the enclosure for this all out build. I was going to mount the Antek Transformer inside but I will put it in a separate enclosure and run an Umbilical Cord to the main preamp enclosure. I will mount the power supply pcb inside the main preamp enclosure as well.
Still thinking of how I will layout the front panel, I will check out some gear and see what I will do.
Hello, I would be very grateful if someone could measure the resistance between 1-4 and 5-4 legs of an original AD797.
The problem with doing that is since the measured circuits in the op amp include semiconductor junctions, the resistance reading reported by the meter will vary with the test current the meter uses to measure resistance. Different meters may use a different test current on any given resistance range, so the meters will report different readings depending on the test current they source. The same meter used to test the junction on the meter's different resistance ranges will show different test results.