To determine the amount of gain one wants, would we need to know in advance before ordering or can it even be changed afterwards.
I think I could definitely need 3 boards for use as a pré amplifier (without volume control), two of those would be used with SE in, differential out, one of them with differential in and SE out. But it's kind of hard to figure out what gain I would want.
I assume I can change the in and output from SE to Differential easy enough but don't quite get the gain option.
I hope you'll offer a suitable power supply down the road. I'd pré-order the boards if I knew that for sure. (and could figure out the gain option
).
I think I could definitely need 3 boards for use as a pré amplifier (without volume control), two of those would be used with SE in, differential out, one of them with differential in and SE out. But it's kind of hard to figure out what gain I would want.
I assume I can change the in and output from SE to Differential easy enough but don't quite get the gain option.
I hope you'll offer a suitable power supply down the road. I'd pré-order the boards if I knew that for sure. (and could figure out the gain option
).
Hi!
The gains are set by 2 thru hole resistors. You can see them on the prototype board on his webpage (R8 and R24, near the top and bottom opamps). Tom will probably provide a table of resistors and gains offered. And with some inventive soldering you can even use SMD resistors if you want. Finally, for the truly adventurous (and I don’t know if Tom approves) there are pin adapters that can be soldered where the thru hole resistors should be and you should be able to change resistors values easily that way without soldering/desoldering. I don’t know if that is possible with this board, but I’ve seen them before.
That being said, I am sure Tom will provide clear answers once he is back from vacation.
Best,
Anand.
The gains are set by 2 thru hole resistors. You can see them on the prototype board on his webpage (R8 and R24, near the top and bottom opamps). Tom will probably provide a table of resistors and gains offered. And with some inventive soldering you can even use SMD resistors if you want. Finally, for the truly adventurous (and I don’t know if Tom approves) there are pin adapters that can be soldered where the thru hole resistors should be and you should be able to change resistors values easily that way without soldering/desoldering. I don’t know if that is possible with this board, but I’ve seen them before.
That being said, I am sure Tom will provide clear answers once he is back from vacation.
Best,
Anand.
Last edited:
Yep. That's exactly my plan.
Indeed. 1206 size resistors (so rather large for ease of soldering) to be specific.
I don't think the hole spacing will allow for an off-the-shelf adapter, but you could easily take two of the 'tulip' pins from a turned-pin IC socket and make them into an adapter that would fit on the board. Stab the resistor into the IC socket pins.
I'm really surprised by all these questions about gain. The description tab on the product page says, "Can be configured with gain by adding two resistors". The Specifications tab says, "Gain - 0 dB - Can be increased by resistor option". The Circuit Topology tab says, "Buffer provides both a balanced differential output and a single-ended (unbalanced) output. In addition, it can be configured to provide gain and/or signal inversion." Yet, there seems to be a lot of confusion about how to increase the gain of the Buffer. Please let me know how I can better communicate this.
Tom
Hi Tom,
I'm just asking a lot of questions due to not being well versed in the options. This is still pretty new terrain for me, contrary to most viewing this thread. I've been following your threads due to your reputation of making great products. I had been eying the THAT driver but that couldn't solve my specific needs. This new product can, but as said, the questions by me are coming from inexperience. I'm a trained mechanical designer, not that well versed in electronics to be honest.
So sorry for all the silly questions, but I'd like to know if a power supply for this universal buffer is on your road map some time in the near future.
I think your description is fine as is, I was just looking for confirmation how it worked exactly. These last two posts have done that for me.
I'm just asking a lot of questions due to not being well versed in the options. This is still pretty new terrain for me, contrary to most viewing this thread. I've been following your threads due to your reputation of making great products. I had been eying the THAT driver but that couldn't solve my specific needs. This new product can, but as said, the questions by me are coming from inexperience. I'm a trained mechanical designer, not that well versed in electronics to be honest.
So sorry for all the silly questions, but I'd like to know if a power supply for this universal buffer is on your road map some time in the near future.
I think your description is fine as is, I was just looking for confirmation how it worked exactly. These last two posts have done that for me.
I think one of the things that will need to be established is how the volume control affects the THD at greater and greater levels of attenuation. We don't usually listen at unity gain or beyond. This was alarmingly obvious in the measurements of the Tortuga LDR seen before (besides the intrinsically high THD in and of itself).
So now we have a Universal Buffer with abysmally low distortion and we need to prove that the addition of a volume control doesn't compromise the abysmally low distortion at low, moderate and high volumes of attenuation. And if that is so, then the name of the volume control, brand, or build becomes immaterial unless the construction quality of the volume control compromises longevity or usefulness. In other words, I don't care if it is a TKD, Alps, Seiden, Gold Point, etc...
This is glaringly obvious from John Siau's work on the Benchmark LA4 preamplifier. They had to design a pretty tricked out relay based volume control and from his comments it was somewhat of a challenging exercise.
I am sure Tom will test this in the future for those who are willing to wait. Looking forward to it.
Best,
Anand.
So now we have a Universal Buffer with abysmally low distortion and we need to prove that the addition of a volume control doesn't compromise the abysmally low distortion at low, moderate and high volumes of attenuation. And if that is so, then the name of the volume control, brand, or build becomes immaterial unless the construction quality of the volume control compromises longevity or usefulness. In other words, I don't care if it is a TKD, Alps, Seiden, Gold Point, etc...
This is glaringly obvious from John Siau's work on the Benchmark LA4 preamplifier. They had to design a pretty tricked out relay based volume control and from his comments it was somewhat of a challenging exercise.
I am sure Tom will test this in the future for those who are willing to wait. Looking forward to it.
Best,
Anand.
Good point,
I dont know what brand of volume pot is inside the Palmer, all I know is its sonically invisible using highly revealing studio grade electronics and monitors.... At anything above low to medium volume as I never use low volume for critical listening.
My unit has been in hard use ( 10 hours a day or more) for two years and its still solid, accurate and feels like a made in Germany high performance piece of kit should.... Highly recomended!
I dont know what brand of volume pot is inside the Palmer, all I know is its sonically invisible using highly revealing studio grade electronics and monitors.... At anything above low to medium volume as I never use low volume for critical listening.
My unit has been in hard use ( 10 hours a day or more) for two years and its still solid, accurate and feels like a made in Germany high performance piece of kit should.... Highly recomended!
They have global distribution, I got mine from Thomann and its now even cheaper under £50.00 ... No brainer!
Palmer Monicon – Thomann UK
Palmer Monicon – Thomann UK
The £125.00 one is the two input / switchable version....Palmer Monicon L – Thomann UK
Then there is the fully active multi function plus digital input / onboard DAC version at £ 250 .... Palmer Monicon XL – Thomann UK
The good news here is it has a DC in for external power supply so you can use high quality power supply ... or even better a nice big lithium battery!
Then there is the fully active multi function plus digital input / onboard DAC version at £ 250 .... Palmer Monicon XL – Thomann UK
The good news here is it has a DC in for external power supply so you can use high quality power supply ... or even better a nice big lithium battery!
Doesn't look like anything fancy: Gearslutz - View Single Post - Palmer Monicon anyone?
It sure would be nice with measurements as well...
Which uses an Alps RK271-series pot: Gearslutz - View Single Post - Palmer Monicon anyone?
The Alps pot will set you back about $15 at Mouser. I've used quite a few different Alps pots and have yet to measure any degradation in any parameter relevant for audio, so I'm not surprised if you perceive them as "sonically transparent".
Tom
Last edited:
Thanks for the info tom, when I looked into building my own passive volume control I found the Bill of Materials (BOM) was nearly £100.00 roughly as follows:
Good Alps pot £ 20 plus nice external volume control
Internals - Solid core silver or Litz wire £10 (1-meter min I could buy)
Cardas silver solder £25 ( would be enough for lots of units!)
Good Neutrik balanced XLR connectors (two inputs plus two outputs)£20.00
Nice wooden case with metal base and soft rubber feet. £ 25.00
Buying things from several different suppliers means paying double or triple shipping....
Good Alps pot £ 20 plus nice external volume control
Internals - Solid core silver or Litz wire £10 (1-meter min I could buy)
Cardas silver solder £25 ( would be enough for lots of units!)
Good Neutrik balanced XLR connectors (two inputs plus two outputs)£20.00
Nice wooden case with metal base and soft rubber feet. £ 25.00
Buying things from several different suppliers means paying double or triple shipping....
Hydrogen Alex, If you're interested in truly professional studio quality volume control, get Penny Giles faders. Much better than Alps in sound quality/accuracy, and new ones are sold from $10 each on Ebay. They are made in UK.
PS: Those fades are used to be sold for $100-300. The reason why they are so cheap these days is there is no market for these, since most professionals are using digital faders (or motorized analog faders) today.
PS: Those fades are used to be sold for $100-300. The reason why they are so cheap these days is there is no market for these, since most professionals are using digital faders (or motorized analog faders) today.
Last edited: