Hi Oliver,
When using 2 Red Baron's in parallel, are 8.2nf caps used for this mod, and
does the 28r I/V resistors (Tube-i-zator) need to be changed?
Best regards,
Ned
Hi Ned,
for the corner frequency between 300-400 kHz you have to calculate the capacitor value for one chip (56R, 8,2pF). Then place this value on each chip for each channel.
Same for the I/V resistor, simply calculate I/V resistor value for one DAC chip (=56R) and place two of these resistors in parallel (=28R).
In short, total capacitance is doubled, total I/V resistor value is halved, turnover frequency remains unchanged.
When using two Red Baron parallel, you need 4x 8,2nF caps and a R I/V of 28R.
Personal announcement
Well my friends it is time again to say thanks to all of you, who like and ordered my pcb´s.
Because i am no developer of electronic circuits but have the knowledge to design pcb´s,
i wanted to give something back to the community.
Since i started with my 1st pcb, the Optical-Volume-Control on 15th October 2009,
a small donation from every sold pcb goes to diyaudio.com
Today i am proud to say that your cumulated donation achieve
$ 3104
Keep on having fun with my pcb´s and best regards
Oliver
Because i am no developer of electronic circuits but have the knowledge to design pcb´s,
i wanted to give something back to the community.
Since i started with my 1st pcb, the Optical-Volume-Control on 15th October 2009,
a small donation from every sold pcb goes to diyaudio.com
Today i am proud to say that your cumulated donation achieve
$ 3104
Keep on having fun with my pcb´s and best regards
Oliver
Last edited:
Bargain Sale
Here you could order my ready build Tube-I-zator test module
(excl. Tubes, Rk & R I/V)
Main Parts
- Nichicon KX Series caps (HV-PSU)
- Panasonic FM Series caps (Heater PSU)
- Mundorf MCap EVO aluminium/oil 2.2µF output caps
- Fairchild ISL9R460PF2 Stealth rectifier diodes
for the special price of
$99
including
Worldwide shipping and paypal fee
If you are interested, please send me a PM.
Bargain Sale
Here you could order my ready build Tube-I-zator test module
(excl. Tubes, Rk & R I/V)
Main Parts
- Nichicon KX Series caps (HV-PSU)
- Panasonic FM Series caps (Heater PSU)
- Mundorf MCap EVO aluminium/oil 2.2µF output caps
- Fairchild ISL9R460PF2 Stealth rectifier diodes
for the special price of
$99
including
Worldwide shipping and paypal fee
An externally hosted image should be here but it was not working when we last tested it.
If you are interested, please send me a PM.
Last edited:
The new Tube-I-zator V3.0
The new Tube-I-zator V3.0
The evolution brings the following changes:
- Anode PSU with Salas SSHV Shunt Reg. onboard
- External B+ Input for usage with other Anode PSU
- Heater PSU with C-R-C filtering
- Heater PSU with Softstart circuit
- Heater PSU Power LED
Thanks to John (-ecdesigns-) for the following suggestions!
- Grid stoppers to prevent unwanted oscillations
- Bias current injection for TDA1541A usage
- Pull-down resistors to keep the coupling cap output at GND-potential
Still on the Module:
- Heater switch for 6N2P or 12AX7 usage
An example for a balanced use (e.g. Bufalo II), you could see HERE.
The PCB has the following data:
Material: FR4 - 2mm
Layers: 2
Board size: 193x157 mm
Surface finish: Immersion Gold
Copper weight: 70µm
Soldermask: Both sides - green
Silkscreen: Legend on top
In Stock
The price will be as followed:
Professional 2-Layer PCB: $30
Worldwide shipping: $ 9
Europe shipping: $ 5
paypal fee: 3,9%
Shipping insurance on buyers request!
A donation of $3 USD to diyAudio will be done for every pcb sold.
A 2nd small failure in my design program needs to expand one of every heatsink mounting holes a bit (1mm).
These two small design failures will be corrected in one of the next batches.
Thank´s in advance for your understanding!
You will find the BOM and Schematic in my blog.
An externally hosted image should be here but it was not working when we last tested it.
The evolution brings the following changes:
- Anode PSU with Salas SSHV Shunt Reg. onboard
- External B+ Input for usage with other Anode PSU
- Heater PSU with C-R-C filtering
- Heater PSU with Softstart circuit
- Heater PSU Power LED
Thanks to John (-ecdesigns-) for the following suggestions!
- Grid stoppers to prevent unwanted oscillations
- Bias current injection for TDA1541A usage
- Pull-down resistors to keep the coupling cap output at GND-potential
Still on the Module:
- Heater switch for 6N2P or 12AX7 usage
An example for a balanced use (e.g. Bufalo II), you could see HERE.
The PCB has the following data:
Material: FR4 - 2mm
Layers: 2
Board size: 193x157 mm
Surface finish: Immersion Gold
Copper weight: 70µm
Soldermask: Both sides - green
Silkscreen: Legend on top
In Stock
The price will be as followed:
Professional 2-Layer PCB: $30
Worldwide shipping: $ 9
Europe shipping: $ 5
paypal fee: 3,9%
Shipping insurance on buyers request!
A donation of $3 USD to diyAudio will be done for every pcb sold.
An externally hosted image should be here but it was not working when we last tested it.
A 2nd small failure in my design program needs to expand one of every heatsink mounting holes a bit (1mm).
These two small design failures will be corrected in one of the next batches.
Thank´s in advance for your understanding!
You will find the BOM and Schematic in my blog.
Nice work Oliver!
neat.
Thanks
Hi.
Can i use Tube-I-zator PCB with PCM1794A? (DDAC 1797 NOS -Doede)
Sure. Please ask Doede witch I/V resistor value , Tubes and Rk value he recommend.
Attachments
Thanks
Sure. Please ask Doede witch I/V resistor value , Tubes and Rk value he recommend.
You should ask Doede about the I/V and Rk resistor value for a SRPP stage like the Tube-I-zator, witch is different from his standard design value
Hi Oliver,
Is is OK to add R26-R31 from your V3 schematic to my V2 boards?
I am running 2 x tube-i-zators v2 in a balanced, dual mono format with 2 x Bullalo IIISEs. I am currently using 20R I/V resistors but have ordered 4 x 30R Rhopoint's to try out.
I obviously don't need the 1541-specific mods but what will the difference be having made the mods?
Any difference in values for balanced/dual mono build?
Cheers,
Crom
Is is OK to add R26-R31 from your V3 schematic to my V2 boards?
I am running 2 x tube-i-zators v2 in a balanced, dual mono format with 2 x Bullalo IIISEs. I am currently using 20R I/V resistors but have ordered 4 x 30R Rhopoint's to try out.
I obviously don't need the 1541-specific mods but what will the difference be having made the mods?
Any difference in values for balanced/dual mono build?
Cheers,
Crom
Just wondering why you are going from 20R to 30R for you I/V resistors?
Good question tmas ;-)
The simple answer is that Rhopoint doesn't have 20R in stock.
The longer answer is that I've been playing with various values of resistor and decided that I am unable to tell any difference. noizas kindly gave me some theory behind the value choice so that I can try the measured approach. I've found that the Sabre produces 3.903mA p-p per channel but still working on finding the output voltage so that I can try out noizas' equations. I've tried posting on twisted pear forum but Russ/Bryan don't seem to want to help. In the meantime, I got impatient ;-)
Cheers,
Crom
Hi Oliver,
Is is OK to add R26-R31 from your V3 schematic to my V2 boards?
I am running 2 x tube-i-zators v2 in a balanced, dual mono format with 2 x Bullalo IIISEs. I am currently using 20R I/V resistors but have ordered 4 x 30R Rhopoint's to try out.
I obviously don't need the 1541-specific mods but what will the difference be having made the mods?
Any difference in values for balanced/dual mono build?
Cheers,
Crom
Hi Crom,
you could add easily the two 1M0 pull down resistors (R30 & R31) to keep the output of the coupling cap at GND potential. Otherwise equipment could be damaged when connected (high voltage on the output when the coupling cap is discharged).
If you haven´t problems with oscillations, you could omit the 1K5 grid stoppers (R26-R29). Because of the new layout for the V3, John recommended to add these resistors.
The values stays also for balanced/dual mono builds.
Best regards,
Oliver
Good question tmas ;-)
The simple answer is that Rhopoint doesn't have 20R in stock.
The longer answer is that I've been playing with various values of resistor and decided that I am unable to tell any difference. noizas kindly gave me some theory behind the value choice so that I can try the measured approach. I've found that the Sabre produces 3.903mA p-p per channel but still working on finding the output voltage so that I can try out noizas' equations. I've tried posting on twisted pear forum but Russ/Bryan don't seem to want to help. In the meantime, I got impatient ;-)
Cheers,
Crom
Hi Crom,
Please keep us posted on your findings. I will be building my dual mono Buffalo 3 with Tube-I-Zator soon.
Please keep us posted on your findings.
No problem, I received the 30R Rhopoints yesterday and fitted them last night. Sounded pretty good immediately but after a couple of hours I completely concur with what Oliver has said. Revelatory !!!! I needed to buy 4, so that's about 60 GBP - no mean sum - but well worth it in my opinion. All the instruments take on a little more of a holographic presentation ... like they have more depth, texture and sort of 3d quality to them...sounds mental, but true. I tried it again this morning and there's even a little less harshness in vocals and perceptively more detail. Perhaps the more detail is because there's less harshness. One thing I probably should do is go back to 30R PRPs to remove the increased resistance from the equation but I'm not sure I can be bothered at the moment - it just sounds stunning.
NB - in my build I've already replaced the 200R Rk with Texas Components but the R I/Vs I was using were the standard BOM PRP9372 (ie I hadn't upgraded the R iv to the texas components)...maybe that's why it was such a big leap for me because I know Oliver has said that the TCC metal films are excellent as Ri/v.
I'm using them with my current fave tube, the full music. I've also got some NOS Mullards which sound great but I love the detail of the FMs.
I should get v2-v3 extra resistors today/tomorrow.
@Oliver - how can I know/measure if I'm getting oscillations?
Cheers,
Crom
Crom,
I am not familiar with the TCC metal films?
Sorry tmas, I was over-shortening...look here:
http://www.diyaudio.com/forums/blogs/dvb-projekt/969-best-sounding-i-v-resistor.html
I was referring to the Texas components corporation resistors that Oliver had recommended in the past.
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