@TJF
Balanced construction is possible, but whether there will be a sound benefit is questionable, because making true balanced output is also not an easy task ...
The output voltage can be set up to 10V ... do you mean as 10Vpp (+5V/-5V) or 10Vp (+10V/-10V)?
For 10Vpp (+/-5V) the R8, R9 is 5k2
For 10Vp (+/-10V) the R8, R9 is 10k, but you must power the output opamps with separated power supply +-15V (jumpers J10, J11, J12, J13 are not installed and instead the separated power supply is here connected)
Balanced construction is possible, but whether there will be a sound benefit is questionable, because making true balanced output is also not an easy task ...
The output voltage can be set up to 10V ... do you mean as 10Vpp (+5V/-5V) or 10Vp (+10V/-10V)?
For 10Vpp (+/-5V) the R8, R9 is 5k2
For 10Vp (+/-10V) the R8, R9 is 10k, but you must power the output opamps with separated power supply +-15V (jumpers J10, J11, J12, J13 are not installed and instead the separated power supply is here connected)
Last edited:
@miro
Sorry, I made a mistake last night. I started from RMS. I actually need about 30Vpp(+15V/-15V)....
Can you maybe give me some more tips? Alternatively, if I want to test a tube output, I see a solution with the AD1865 using a resistor. This will not work with AD1862. Do you have a good idea without putting a complete transistor I/V in front of it here or does it make no sense at all?
I have to go balanced into the power amp in any case. Is it a good solution to build the AD1862 balanced already (2 pcbs with 2x2 pieces)?
Sorry, I made a mistake last night. I started from RMS. I actually need about 30Vpp(+15V/-15V)....
Can you maybe give me some more tips? Alternatively, if I want to test a tube output, I see a solution with the AD1865 using a resistor. This will not work with AD1862. Do you have a good idea without putting a complete transistor I/V in front of it here or does it make no sense at all?
I have to go balanced into the power amp in any case. Is it a good solution to build the AD1862 balanced already (2 pcbs with 2x2 pieces)?
30Vpp is quite high output and you will need a differential preamp.
No one has tried balanced connection with this DAC yet, this should be possible with DATA invert for one DAC.
I have no experience with balanced applications. All my input cables are not longer as 2 meters. Balanced topologies have parameters benefit, but are challenging to lookup for sound quality (it's not as easy as replacing one opamp).
No one has tried balanced connection with this DAC yet, this should be possible with DATA invert for one DAC.
I have no experience with balanced applications. All my input cables are not longer as 2 meters. Balanced topologies have parameters benefit, but are challenging to lookup for sound quality (it's not as easy as replacing one opamp).
Can you specifically recommend something suitable to me? Link...?
No idea to a simple voltage output (->tube) for AD1862?
Hi,
Nautiboy has talked here about an hybrid tube/transistor stage, better for you to follow a member with a proved design/kit.
You can also look at Andrea Ciuffoli site that made an AD1865K tube stage output that a member from Vietnam here is selling in the shops section.
Does your pre or integrated amp only has balanced inputs or do you talk about symetric design inside ?
Notice some of the oaps in the list have so very low drift than they can be used without serie DC blocking cap before the single ended RCA and this is a huge advantage if the amp/speaker combo has great resolution skills...
A tube solution ask an output traffo or DC blocking MKP cap that makes it expensive, not saying basic tubes are not sometimes the best choices, NOS or sorted tubes with some makes it even more expensive, but here I can not confirm much more as it's all about the pretty coloration you best prefer (what music is at the end whatever the design).
So if your amp is just symetric by design but still single ended at its input, then the actual design is perfectly fine as said by Miro.
IMHO, better to focus first on the front end quality and the powersupply quality : C-Core traffos, ....
I'm not saying you can not tubes, but it's just ask a specific knowledge and experience as devils are in the details as often if not always
Anyway, no problem with Calvin design, he is a very reliable member
Nautiboy has talked here about an hybrid tube/transistor stage, better for you to follow a member with a proved design/kit.
You can also look at Andrea Ciuffoli site that made an AD1865K tube stage output that a member from Vietnam here is selling in the shops section.
Does your pre or integrated amp only has balanced inputs or do you talk about symetric design inside ?
Notice some of the oaps in the list have so very low drift than they can be used without serie DC blocking cap before the single ended RCA and this is a huge advantage if the amp/speaker combo has great resolution skills...
A tube solution ask an output traffo or DC blocking MKP cap that makes it expensive, not saying basic tubes are not sometimes the best choices, NOS or sorted tubes with some makes it even more expensive, but here I can not confirm much more as it's all about the pretty coloration you best prefer (what music is at the end whatever the design).
So if your amp is just symetric by design but still single ended at its input, then the actual design is perfectly fine as said by Miro.
IMHO, better to focus first on the front end quality and the powersupply quality : C-Core traffos, ....
I'm not saying you can not tubes, but it's just ask a specific knowledge and experience as devils are in the details as often if not always
Anyway, no problem with Calvin design, he is a very reliable member
Last edited:
Hi diyiggy,
thank you for your post. I know Nautiboy from his Aikido-build at another place...
I know Andrea Ciuffolis design. That is unfortunately not for me. I have a very special plan without further compromises and a very special plan. The balanced version is a "must".
I see that my idea with AD1862 ("balanced") is not very realistic. Also because of the kind of output. I think at the moment, the best would be to use a normal (unbalanced) AD1865 and go with something like Broskies Balancer. I could reach the goal with the wanted gain and the wanted output impedance. But with an own PSU, which can give the nessessary current for B+ Voltage. AD1865 could also be used with Transistor I/V. I wouldn't use any hex inverters for balanced operation. You sometimes have to take things as they are meant to be
thank you for your post. I know Nautiboy from his Aikido-build at another place...
I know Andrea Ciuffolis design. That is unfortunately not for me. I have a very special plan without further compromises and a very special plan. The balanced version is a "must".
I see that my idea with AD1862 ("balanced") is not very realistic. Also because of the kind of output. I think at the moment, the best would be to use a normal (unbalanced) AD1865 and go with something like Broskies Balancer. I could reach the goal with the wanted gain and the wanted output impedance. But with an own PSU, which can give the nessessary current for B+ Voltage. AD1865 could also be used with Transistor I/V. I wouldn't use any hex inverters for balanced operation. You sometimes have to take things as they are meant to be
Your welcome. If you need balanced then no question, but if you don'need long length and the amp has not a lower quality* SE input than the balanced then SE is perfectly as good and you don't have to ask yourself about gain and adaptation impedance as it's 99% of the time good enough.
Imo you are wrong if I can permit myself to say so. First the AD1862 is a far better choice for just few bucks and a collector (a must). Then passive I/V a a far better choice as well than internal AD1865 oap.
Can you say us more about the amp model/design ?
* : sometimes the amp has better SE input than the balanced one which is made with THAT dip chips... Sometimes it's the opposit, you need to know what sort of beast is the amp; sometimes you have not the input choice (PA amps !)
Imo you are wrong if I can permit myself to say so. First the AD1862 is a far better choice for just few bucks and a collector (a must). Then passive I/V a a far better choice as well than internal AD1865 oap.
Can you say us more about the amp model/design ?
* : sometimes the amp has better SE input than the balanced one which is made with THAT dip chips... Sometimes it's the opposit, you need to know what sort of beast is the amp
; sometimes you have not the input choice (PA amps !)
Last edited:
What do you mean exactly by "collector"? We could not discuss "balanced" vs. "unbalanced". Years ago I had an AD1862, an final tuned TEAC-VRDS 25x with external PSU. Then I found a better way (using tuned Tact, TI, Class D). Now I will go a way back to DACs. AD1862/AD1865 with an other kind of stage. But the solution must stay in balanced harmony with the rest.