Russ White said:
It was surprisingly simple to put together. Just fired it up, biased and it ran. Almost a little too good 🙂 I will post my bom and some tips soon.
Excellent. 🙂
I enjoy listening to mine, I use it regularly.
Being able to zero the offset is very helpful for very sensitive headphones, as it ensures there is no deflection of the transducers.
Cheers!
Russ
I enjoy listening to mine, I use it regularly.
Being able to zero the offset is very helpful for very sensitive headphones, as it ensures there is no deflection of the transducers.
Cheers!
Russ
Hi MrMajestic and Russ.
Boards received today, great PCB, thanks ! 😉
I have ordered missing parts too.
Waiting for the PSU.
I will let you know when finished.
Boards received today, great PCB, thanks ! 😉
I have ordered missing parts too.
Waiting for the PSU.
I will let you know when finished.
Yes sure I will, but actually dont know when exactly.
Wondering about feeding the Diamante with USB Opus input signal.
What is the value of your pot ? Nice small PCB too, yes curious.
Wondering about feeding the Diamante with USB Opus input signal.
What is the value of your pot ? Nice small PCB too, yes curious.
korben69 said:
I used a 50K pot, because thats what I had at home. Russ said a 10K is what he would use. He stated that you should change RZ to 100K if you use a 50K pot. I didnt do that and its sounds fine to me 🙂
Hallo Mr. Russ
Compliments for your last creature seen in post n.126.
I like very much the evolution and I have some questions:
-It's ready to made or it need further tuning?
-can you post simulated performances at various frequency,loads and levels?
-where are placed (and what values) the offset and bias trimmer?
-what bias curren is optimal for the output stage?
-what is the max. power supply voltage for this amp?
Thank you very much and I whish encourage you and everyone is interested(...MrMajestic...)to follow this great promising project and if possible make a prototype with real world measures......
Regards
Semola
Compliments for your last creature seen in post n.126.
I like very much the evolution and I have some questions:
-It's ready to made or it need further tuning?
-can you post simulated performances at various frequency,loads and levels?
-where are placed (and what values) the offset and bias trimmer?
-what bias curren is optimal for the output stage?
-what is the max. power supply voltage for this amp?
Thank you very much and I whish encourage you and everyone is interested(...MrMajestic...)to follow this great promising project and if possible make a prototype with real world measures......
Regards
Semola
Hi Mr Majestic and Russ,
I've begun boards soldering, still waiting for some missing parts.
Noob questions
1° - C3/C4
I've got some Z5U, does they fit intead of Polyester/Polyprop ? (same value 220nF/50v Ceramic).
2° - C1/C2
I've used some Elna 220µf/63v vs Panasonic, do you think the result will be affected ?
Thanks for the answers 😉
I've begun boards soldering, still waiting for some missing parts.
Noob questions
1° - C3/C4
I've got some Z5U, does they fit intead of Polyester/Polyprop ? (same value 220nF/50v Ceramic).
2° - C1/C2
I've used some Elna 220µf/63v vs Panasonic, do you think the result will be affected ?
Thanks for the answers 😉
korben69 said:
1. Im guessing its not a good idea, but I'll let Russ give the final verdict.
2. Should'nt make a big difference.
korben69 said:
1) No. You can use ceramic if you can find some C0G/NP0, but that is a large size for them.
2) They should be fine.
korben69 said:
Hello,
1) Just about any capacitor of a low impedance can be used there with no ill effects. Use what you have and never fear. Later you can replace with film caps if you like. Your Z5U will work just fine.
2) No. 🙂
Your welcome.
Cheers!
Russ
Thanks to the Trio ! 
I'm waiting for missing parts to be delivered.
So I won't use Z5U, I just have them under the hand...
I'll let you know when it'll be finished.
Cheers
I'm waiting for missing parts to be delivered.
So I won't use Z5U, I just have them under the hand...
I'll let you know when it'll be finished.
Cheers
Hello
You should be very carfull when selecting capacitor types.
The mentioned type Z5U is known for its large tolerance, this is also the problem with the Y5V type.
Tolerances is as follow:
Nominal: +80 - -20%
Temperature dependent: +20 - -50%
Further more the capacitance is depending op the applied DC-voltage, and at only a few volts the remaining capacitance is less than 30% of the nominal.
This could give som very interesting problems with oscillations because of warying capacitance.
Some information could be found here:
http://en.wikipedia.org/wiki/EIA_Class_2_dielectric
Othewise try to search on the different types, AVX and Murata have a lot of information on this issue.
A "middle of the road" approach could be to use X7R or similar, they have good tollerances in all aspects (but not as good as COG/NP0).
Best regards
Jørn
You should be very carfull when selecting capacitor types.
The mentioned type Z5U is known for its large tolerance, this is also the problem with the Y5V type.
Tolerances is as follow:
Nominal: +80 - -20%
Temperature dependent: +20 - -50%
Further more the capacitance is depending op the applied DC-voltage, and at only a few volts the remaining capacitance is less than 30% of the nominal.
This could give som very interesting problems with oscillations because of warying capacitance.
Some information could be found here:
http://en.wikipedia.org/wiki/EIA_Class_2_dielectric
Othewise try to search on the different types, AVX and Murata have a lot of information on this issue.
A "middle of the road" approach could be to use X7R or similar, they have good tollerances in all aspects (but not as good as COG/NP0).
Best regards
Jørn
re: gain and calculation
Hi
I've seen a couple of posts here with regards to gain calculation to obtain a gain of 4. I noticed that the resistor values were completely different. Is it not possible to change just one resistor keeping the other fixed?
R
Hi
I've seen a couple of posts here with regards to gain calculation to obtain a gain of 4. I noticed that the resistor values were completely different. Is it not possible to change just one resistor keeping the other fixed?
R
Hi, can anyone confirm the dimensions of the board? I'm interested in having a few of these made at OurPCB, and their quoting process asks for the size.
As a side note, I'm interested in hearing from anyone wanting to join me in a mini-group-buy to offset tooling costs. I only have a use for 5 boards, and a rough estimate shows the order would need to reach about 15 to be economical.
Of course, if a proper group buy is likely to be set up soon, I'll wait for that.
As a side note, I'm interested in hearing from anyone wanting to join me in a mini-group-buy to offset tooling costs. I only have a use for 5 boards, and a rough estimate shows the order would need to reach about 15 to be economical.
Of course, if a proper group buy is likely to be set up soon, I'll wait for that.
TheSeekerr said:
The boards are 101,51x63,57mm, give or take a few mm 🙂 Hopefully a groupbuy will get up and running after the last four boards are built.
I would be interested in a few boards. Quantity I buy will depend on pricing & shipping to US.
Definitely a project I want to build for my Sennheiser's.
Definitely a project I want to build for my Sennheiser's.
Well, if you want 2 boards, I'm up to 7 boards total, and 2 boards would cost you $22 each including shipping. If you want 5 boards, I'd be up to 10 boards total, and they'd cost you $14 each including shipping. If the total order reaches 20 boards, those 5 boards now only cost $10 per board, including shipping.
All numbers are approximate, but pretty close.
So, yeah, not so good value at the moment, but the price goes down fast if you want 5>15 boards, or if more people are interested.
(Shipping would be via prepaid airmail satchels, costing $15, and capable of shipping about 15 or 20 boards, depending on what they weigh)
All numbers are approximate, but pretty close.
So, yeah, not so good value at the moment, but the price goes down fast if you want 5>15 boards, or if more people are interested.
(Shipping would be via prepaid airmail satchels, costing $15, and capable of shipping about 15 or 20 boards, depending on what they weigh)