Hi Ivan,
A little over a year ago you provided me with a set of output transformers for my four deck PCM 1704 DAC. The result was very good. After a few months of burning in, the sound quality only got better. Great sound stage. In short, I am very satisfied
At the moment I am working on a new DAC project. It concerns the design by Doede Douma of the DDDAC with the PCM1794. I also use 4 decks for this design. I would also like to equip this project with a set of your output transformers.
I understand that you have already sent Doede Douma a set to test. but you have not got the results back.
Because I have a lot of confidence in your transformers, I would like to include these again in my new project. Of course I'll let you know the results.
Can you tell me what the current costs are to order a set?
A little over a year ago you provided me with a set of output transformers for my four deck PCM 1704 DAC. The result was very good. After a few months of burning in, the sound quality only got better. Great sound stage. In short, I am very satisfied
At the moment I am working on a new DAC project. It concerns the design by Doede Douma of the DDDAC with the PCM1794. I also use 4 decks for this design. I would also like to equip this project with a set of your output transformers.
I understand that you have already sent Doede Douma a set to test. but you have not got the results back.
Because I have a lot of confidence in your transformers, I would like to include these again in my new project. Of course I'll let you know the results
.Can you tell me what the current costs are to order a set?
Thanks Richard for the feedback and kind words 🙂Hi Ivan,
A little over a year ago you provided me with a set of output transformers for my four deck PCM 1704 DAC. The result was very good. After a few months of burning in, the sound quality only got better. Great sound stage. In short, I am very satisfied
At the moment I am working on a new DAC project. It concerns the design by Doede Douma of the DDDAC with the PCM1794. I also use 4 decks for this design. I would also like to equip this project with a set of your output transformers.
I understand that you have already sent Doede Douma a set to test. but you have not got the results back.
Because I have a lot of confidence in your transformers, I would like to include these again in my new project. Of course I'll let you know the results
Can you tell me what the current costs are to order a set?
It is funny that I have read your post doing two things: working on a new project based on PCM1704 and chating with Kartick (@kartick) who is the owner of my trafos and 4 boards DDDAC. 🙃
Regarding results from Doede, well... We have discussed technical things privately via emails for long time and finally, conceptually we have agreed and came to a mutual conclusion regarding usage of my transformers with his DAC. It will be not correct if I will show his opinion here in terms of comparison with other output options for his DAC, but I can definitely say that my trafos works and Doede preferred a larger version of my trafos. I can only hope Doede will find time someday to say more about it.
Since we remembered DDDAC project, so here is the acoustical recording of the system with 4xDDDAC boards + my larger trafos. Thanks again @kartick for sharing the real "evidences" 😁
Please extract the zip-file and find mp3 inside.
p.s. Strange but I can't upload it on soundcloud due to copyright restrictions. Did they really thought all the previous uploads was my own singning (was no copyright labeling)?😇
Thanks.
Ivan.
$170 for smaller trafos (like you have) and $500 for larger trafos
WW shipment is $35
thanks for your comment,
Good to hear that Doede has tested the transformers. I hope we get to hear the results one day.
Was Doede also able to test the large version of the transformers?
What is your personal opinion about the large transformers compared to the small version. And is it worth the extra cost?
regards,
Richard
Sure he did for both.
If in two words: bigger sound. I can state that I can't use smaller version within my projects anymore. In terms of complexity of manufacturing it is approximately within the same if to make 3 pairs of smaller trafos or one pair of larger trafos. But I would like to leave possibility for smaller trafos for very new users only, but for those who has already tried and like it I would definitely recommend the larger version.
All guys who tried larger trafos after small agreed that it is simply better. Usually (90%) of feedbacks are addressed to me privately and I simply can't show them here. But recently here was a feedback btw about it: https://www.diyaudio.com/community/threads/output-transformers-for-dacs.327794/post-6995718
So I understand that your preference is clearly for the large transformers in terms of sound quality.
Is it also technically possible to explain why the sound quality is better by means of a larger output transformer?
Or in other words, what are the technical differences between the large and the small transformer that can explain the sound improvement.
I know the importance of technical approach, but still... I do not want to build the superiority theory based on measurements as for me music and sound is an art more, than boring measurements.
However... Below pic can't explain all the things but quite revealing explanation at least:
THD plots for both transfomers versions within the same conditions:
However... Below pic can't explain all the things but quite revealing explanation at least:
THD plots for both transfomers versions within the same conditions:
Ivan,
I'm somehow can't start a PM anymore. Even though I'm not a new member
Can you start a PM with me so I can reply on that.
https://www.diyaudio.com/community/threads/new-members-can-not-send-private-messages.384831/
Is there an active analog stage driving the transformers, or are you using a DAC that is capable of driving them directly? Some years ago I built a DAC that drives a pair of Lundhal line transformers directly, at it has been a DAC killer for a long time.Hello everyone who looking for Sound!
After years of expirience the output transformers for current and voltage output DACs have been developed. Transformers tested with following DACs: ES90x8S/K2M/PRO/Q2M, AK4x9x, PCM63/58, PCM1702/04, AD1862/65, PCM1792, PCM1794A, TDA1541/43, DSC dac. Speaking in general, transformers can be suited for any current or voltage DAC both in SE or PP modes.
These transformers are made on high permeable cores, have the low DC resistance at desirable inductive impedance to achieve the best frequency response of the DAC. Transformers provides significant sound quality improvement compared to other output versions. Your music will begin to live a new life, it will sparkle with a naturalness without plastic nervousness
Here are some impressions from iancanada IanCanada's Latest RPi GB Goodies Impressions... and your tweaks, mods and hints...
And here is the page from Andrea Ciuffoli: DSC Output transformers test
Dimensions: OD=47mm, H=24mm, thickness=0.3мм
Frequency Responce of transformer with ES9038q2m at 1.4VRMS (~8kOhm in secondary loaded on 100pF cable): 20Hz=-0.3dB, 20kHz=-0.2dB (rel.1kHz):
View attachment 705302
Same, but with 470pF in parallel with secondary:
View attachment 705303
The possible output level depends on the output current of the DAC (and I/V resistance). In practice it sounds without problems on LF and HF with +/-2mA DAC types such as PCM63\TDA1541 at 2Vp level (1.4VRMS). Less powerfull DACs like PCM58 with +/-1mA have good enough LF even with 1.3Vp witout next buffers.
Here is an example of connection:
View attachment 705329
The prices for matched pair (13 pin max-mill version) are:
2 coils = 170 USD
3 coils = 190 USD
4 coils = 220 USD
6 coils = 250 USD
Worldwide shipping is included (small package service). Usually takes 2-3 weeks for delivery.
*it is possible to send with insurance (~30$) and by EMS (~40$).
Various assembled PCBs are available from $205 to $320 (active version for Ian's DAC for example).
PM me for futher ordering details here on forum or to bisesikATgmail...
Lead time depends on existing orders. Thanks.
BR, Ivan.
The relevant current documentation for my transformers available here: Output transformers for DACs
I do not practicing active stage between DACs and transformers. Active stage can be applied after my transformers if an extra amplification of signal is needed. In case of old weak DACs I offering to use transformers in serries connection with current (follower) bufer stage before the next transformer.
hi bisesik,
I have been using transformer i/v for one of my dacs for a number of years. The DAC is an ESS9018 based DAC that syncs clocks back to an SD card based transport. As shown here in this link - I bought it without the op-amp based I/V module: link
I threw together a quick schematic of the I/V and downstream components:
U1 - ESS9018D (+)
U2 - ESS9018D (-)
I use 4 dac outputs in parallel per channel but the DAC is dual mono so I could use 8 per channel. 4 was more straightforward to connect and I'm lazy, hah. I'd actually forgotten.
R1,R2 80 ohms
L1 Sowter 3575 (10k:10k)
L2 Tapped autotransformer stepped volume control
R3 22kohm amplifier input impedance
I set it up this way to try it and never touched it after. It sounds pretty great, but it could use a bit more voltage output.
I'm about to put the DAC into a proper enclosure and I was looking at more purposeful i/v transformer options when I came across yours. The Sowters were something I already had in the parts box.
What would you advise for my situation? The tapped autotransformer volume control adds a complication. The more voltage from the I/V the greater the step down from the autotransformer for the same volume level, other things being equal.
I'm going to do some research on my own, but it would be great to have your experienced input.
Thanks!
I have been using transformer i/v for one of my dacs for a number of years. The DAC is an ESS9018 based DAC that syncs clocks back to an SD card based transport. As shown here in this link - I bought it without the op-amp based I/V module: link
I threw together a quick schematic of the I/V and downstream components:
U1 - ESS9018D (+)
U2 - ESS9018D (-)
I use 4 dac outputs in parallel per channel but the DAC is dual mono so I could use 8 per channel. 4 was more straightforward to connect and I'm lazy, hah. I'd actually forgotten.
R1,R2 80 ohms
L1 Sowter 3575 (10k:10k)
L2 Tapped autotransformer stepped volume control
R3 22kohm amplifier input impedance
I set it up this way to try it and never touched it after. It sounds pretty great, but it could use a bit more voltage output.
I'm about to put the DAC into a proper enclosure and I was looking at more purposeful i/v transformer options when I came across yours. The Sowters were something I already had in the parts box.
What would you advise for my situation? The tapped autotransformer volume control adds a complication. The more voltage from the I/V the greater the step down from the autotransformer for the same volume level, other things being equal.
I'm going to do some research on my own, but it would be great to have your experienced input.
Thanks!