Hi frozen wing,
i tried transformer output with Buffalo24 (ES9008) and i really liked the sound quality (it seems to me better then the IVY), here are description of my setting and some measures. I think it is possible to get better results with a proper configuration of input and output (respect to the transformer) impedance matching as described here and in the other thread. Till now i had no time to try, when i will try i will let you know.
Ciao
Andrea
i tried transformer output with Buffalo24 (ES9008) and i really liked the sound quality (it seems to me better then the IVY), here are description of my setting and some measures. I think it is possible to get better results with a proper configuration of input and output (respect to the transformer) impedance matching as described here and in the other thread. Till now i had no time to try, when i will try i will let you know.
Ciao
Andrea
Frozen wing, I just did some mods to a Musiland DAC that involved outputting I2S to the cheap 2 channel Vout Sabre DAC (ES9022) & it's the best sound I've heard from this unit. http://www.diyaudio.com/forums/digital-source/155622-musiland-01us-usb-dac-i2s-into-sabre.html
I know this isn't what you asked but I'll be using transformers on the full Sabre DAC when I build it (ES9008). Besides anbello, there are others that posted on the Buffalo thread who have used transformer - all reported a very natural sound. Gordon Rankin from Wavelength also uses trafos on his Sabre implementation!
anbello, the thd of the Sabre at LF looks higher than the CS4398 - how did they compare sound-wise?
I know this isn't what you asked but I'll be using transformers on the full Sabre DAC when I build it (ES9008). Besides anbello, there are others that posted on the Buffalo thread who have used transformer - all reported a very natural sound. Gordon Rankin from Wavelength also uses trafos on his Sabre implementation!
anbello, the thd of the Sabre at LF looks higher than the CS4398 - how did they compare sound-wise?
I hope that this higher THD can be cured by a better interfacing of the trafos, anyway i liked more the ES9008 + trafos then the CS4398 + trafos because of a more natural sound and higher capacity to localize the instruments on the soundstage.
Ciao
Andrea
huh?? are you using 9008 in the acko jon? i'm going for 9012 dont need multichannel
still deciding between transformers and the B1 buffer stage, I have been wanting to use traffos with the sabre for a while as I love the elegance and simplicity that is possible with transformer output, but I also have a weakness for high quality film caps
Yup, I will be using 9008 in the Acko board eventually but maybe starting with 9012. What I was referring to in my post above was a cheap 2 channel Vout DAC that Sabre also launched (9022?). My brief exposure to transformers to date as output stage to Vout DACs, has proven to me that they are far superior to an op-amp based o/p stage. Haven't done much testing versus high value, good quality film caps, as I don't own any! Don't know how they would stack against a well designed discrete stage? But I'm happy so far with what I hear!
Yes, Revintage, most who have tried it in voltage mode in this way say it sounds better. Why do you say that it must be at least 10K Zin trafos? I don't see any recommended minimum impedance in the Sabre datasheet
LL1676 w/ WM8741
Hi,
I just started a project in which I intend to do something quite similar - take the differential voltage output of a Wolfson WM8741 DAC chip (which has a DC offset of 2v5) and 'convert' it with a Lundahl LL1676 from balanced (kind of) to unbalanced for further amplification with two parallelled E182CC tubes etc. Will be interesting how that will relate to your findings, sonically and overall
Best,
Robert
Hi,
I just started a project in which I intend to do something quite similar - take the differential voltage output of a Wolfson WM8741 DAC chip (which has a DC offset of 2v5) and 'convert' it with a Lundahl LL1676 from balanced (kind of) to unbalanced for further amplification with two parallelled E182CC tubes etc. Will be interesting how that will relate to your findings, sonically and overall
Best,
Robert
Don't know about the Buffalo.
I've tried a series resistor on the input of the trafo but much prefer a resistor across the primaries - the series R seems to deaden the sound (loudness or dynamics, I'm not sure)
Does it mean that you can just have one transformer between a voltage dac output and a tripath amp input AND just add a pot (without any cap for DC coupling) ?
Where do you connect the pot ?
Can we use the pot across the primary instead of the R load?
Thanks
Michel
Hello !
I'm using a Sabre Buffalo24.
I've tried many 600/600 transformers (Utc, Tamura, various Jensen) , with, for all of them, a lack in low frequencies
Then changed to upper impedance : Edcor, Rane, Jensen , Lundahl, then I got a better response with low frequencies
I found my "Heaven" with Jensen JT-11P1, 10k/10k, , low, mid,trebble, everything is better !!!
Maybe someone would say "Jensen are very expansive " ! yes but the results given by a Jensen (140$/pair) is far far far away from a UTC (~100 $/pair) !
I ve added 100 Ohms on +-, and 3nF on primary side, only to filter HF, and on secondary , 13k + 620pF , to a McIntosh C24 pre
What a happiness !!!
R.C.
I thought I posted this already but here goes anyway:
So does the analog outs from the Sabre work best into 10K? I can't find any mention of minimum impedance for the Vouts - it does in other Vout DACs datasheets, doh!
Did you try a series resistor of 10K with your other 600:600 transformer & the Sabre DAC?
Hello !
Among many transformers 600/600 I've tried with Buff24, I've noticed as a first conclusion is that the best listening was always with transfos which had the upper DCR, this is why UTC A-20, with 72-75 Ohms gave a "good" result...
I've tested 600/600 transfos, with up to 2 x 1.2k , and stopped to think about : if you add more resistance , it's become a voltage divider, and the level at the secondary output becomes very low
The input impedance of each side of the Buffalo (+ and -) are something like 185 Ohms, if you insert 2 x 1k, the result gives you 1/5 of the primary voltage
The fisrt try with a high impedance was Edcor 10k/10k, 13$ each, and a better result than any 600/600...I was on the good way ....
The Jensen 10k/10k I choose are about 1.5k primary DCR, so the ratio Source/load is about 9.
I don't want to say that my solution is the best, but the "best simple solution" !
R.C.
Among many transformers 600/600 I've tried with Buff24, I've noticed as a first conclusion is that the best listening was always with transfos which had the upper DCR, this is why UTC A-20, with 72-75 Ohms gave a "good" result...
I've tested 600/600 transfos, with up to 2 x 1.2k , and stopped to think about : if you add more resistance , it's become a voltage divider, and the level at the secondary output becomes very low
The input impedance of each side of the Buffalo (+ and -) are something like 185 Ohms, if you insert 2 x 1k, the result gives you 1/5 of the primary voltage
The fisrt try with a high impedance was Edcor 10k/10k, 13$ each, and a better result than any 600/600...I was on the good way ....
The Jensen 10k/10k I choose are about 1.5k primary DCR, so the ratio Source/load is about 9.
I don't want to say that my solution is the best, but the "best simple solution" !
R.C.
Thanks Ciu,
I'm a little confused & would like to ask some questions if I may:
Thanks for your help in this - I find transformers confusing so any help is appreciated.
I'm a little confused & would like to ask some questions if I may:
Does a 600:600 transformer have a primary & secondary of 600ohm? I don't understand your ref to UTC A-20 of 72ohm!
Is this 185ohm measured or did you get it from a datasheet?
Thanks for your help in this - I find transformers confusing so any help is appreciated.
Yes, sure, but may be unable to answer all of them (lack some vocabulary ) !!!
About the transformer, like UTC A-20 :
The given value is a 600/600 if you connect all primaries in series , but this is the impedance , not the DCR : dcr is ~75 Ohms (pure resistive windings)
The inductance L is not (never) given,
Z = L 2Pi x F
When the transfo receives a low frequency, the impedance Z is rather low (how much ? don't know !),the Buffalo gives a lot of current, and with a internal resistance, the voltage goes down, and you feel a lack in low frequencies...
With high frequencies...Z goes upper, the output current is low, ....
The value of 180 ohms, has an internal impedance of the Buffalo is given, in many places, even in ESS short sheet, the chip ESS9008 is in fact 8 dacs coupled 4 by 4, (4 L & 4 R) each "small-dac" having ~800 Ohms internal impedance .
Have a look on Buffalo posts, page 48 to 50, some idea to run Buffalo in "current mode" with transfos...
Hope this helps ?
R.C.
About the transformer, like UTC A-20 :
The given value is a 600/600 if you connect all primaries in series , but this is the impedance , not the DCR : dcr is ~75 Ohms (pure resistive windings)
The inductance L is not (never) given,
Z = L 2Pi x F
When the transfo receives a low frequency, the impedance Z is rather low (how much ? don't know !),the Buffalo gives a lot of current, and with a internal resistance, the voltage goes down, and you feel a lack in low frequencies...
With high frequencies...Z goes upper, the output current is low, ....
The value of 180 ohms, has an internal impedance of the Buffalo is given, in many places, even in ESS short sheet, the chip ESS9008 is in fact 8 dacs coupled 4 by 4, (4 L & 4 R) each "small-dac" having ~800 Ohms internal impedance .
Have a look on Buffalo posts, page 48 to 50, some idea to run Buffalo in "current mode" with transfos...
Hope this helps ?
R.C.
Hey Ciu,
Your findings are correct. Any suggestion to run a voltage DAC(Sabre is both) at 600ohm with series resistors is a mistake. I am sure this sounds great.
What you should try though, if you haven´t yet, is to run your Jensen without secondary loading more than your preamp(100k?). Then load the primary with a parallell pure resistive load without series resistors. If you absolutely want filtering you do this on the primary parallell to the loading resistor. This off course is dependant on transformer but most of them like light loads.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.