In most builders feedback BC327 was the preference. Usually described as more resolved in the upper bass and softer in the highs. That's not excluding the BC560's more upfront result suiting some system better. I recommend female mounting pins for easy exchange and evaluation.
Something like that: A Low Power, Low Cost, Differential Input to a Single-Ended Output Amplifier | Analog Devices
Or a line balancing transformer used the other way around.
Through such solutions you can drive a single ended input circuit from a differential source.
To build a balanced preamp takes four channels to use them as two phases per channel.
Or a line balancing transformer used the other way around.
Through such solutions you can drive a single ended input circuit from a differential source.
To build a balanced preamp takes four channels to use them as two phases per channel.
Today I had the opportunity to listen to my Dcg3 vs a pricey prima luna tube preamp. Amps were CJ premier 140 monos. Expensive turntable with Lyra and big Vienna acoustic speakers.
This is not my system...but I stuck the DCG3 and a pass b1 in there because the owner was interested.
The owners comment was “this is just as good as the prima Luna”.
Honestly, I felt the DCG3 was heavier, and had more highs and lows than the tube preamp. Far more dynamic as well. Taller soundstage and more vivid.
Where the prima Luna was perhaps better was it was less grainy, but it had a far lighter weight presentation and did not image any better than the dcg3 I felt.
Pass b1 sounded like a more extended version of the Prima Luna, more crisp but at the same time similar bass. It actually sounded more similar to the prima Luna than the dcg3.
Personally, I don’t the money for this kind of system. What was gratifying to me was that my DCG3 can compete with a $4000 preamp. I do not get the opportunity to compare diy stuff to truly high end commercial pieces often. And it’s extremely good to know that my diy efforts are on par or better than commercial stuff.
Did I mention my Dcg3 is only single mono with lm317/337 regs?
Nice work Salas.
This is not my system...but I stuck the DCG3 and a pass b1 in there because the owner was interested.
The owners comment was “this is just as good as the prima Luna”.
Honestly, I felt the DCG3 was heavier, and had more highs and lows than the tube preamp. Far more dynamic as well. Taller soundstage and more vivid.
Where the prima Luna was perhaps better was it was less grainy, but it had a far lighter weight presentation and did not image any better than the dcg3 I felt.
Pass b1 sounded like a more extended version of the Prima Luna, more crisp but at the same time similar bass. It actually sounded more similar to the prima Luna than the dcg3.
Personally, I don’t the money for this kind of system. What was gratifying to me was that my DCG3 can compete with a $4000 preamp. I do not get the opportunity to compare diy stuff to truly high end commercial pieces often. And it’s extremely good to know that my diy efforts are on par or better than commercial stuff.
Did I mention my Dcg3 is only single mono with lm317/337 regs?
Nice work Salas.
AntonyA, I have built a balanced unit as described by Salas and am using it to feed a SE amplifier by using a Jensen JT11P1 as input to the power amp. I have wired it into the end of the interconnect for each channel from the DCG3 to the power amp. Works and sounds great. Needs no electronics which always leaves some signature.
nash
Salas, I have built a DCG3 a longer while ago. I was never really happy with it beside my other Pre/Headamps, which are a very old Raphael tube pre, a Whammy, a USSPA and a DCB1. All of them share a dominant 2nd harmonic distortion profile, which should the DCG3 show as well, when I look at your measures at the very beginning of this thread. It does not, as I found out recently. I have dominant 3rd harmonic and the sound is like that. I have it running at about 120mA and a stereo PSU. Since I would like to get out its abilities I ask you for help. Pls see here my measures.
BR Ernst
BR Ernst
Attachments
Finally getting mine sorted in a proper chassis.
Thick bamboo chopping block for a base and then some extruded aluminium and gloss black acrylic. Hope it looks nice when finished.
More work to do but I'm getting there!
Thick bamboo chopping block for a base and then some extruded aluminium and gloss black acrylic. Hope it looks nice when finished.
More work to do but I'm getting there!
Attachments
I've dropped the gain on my DCG3 to 2x (499 Dale CMF55) and changed the quad of BC560C's to Diotec BC327-40's. This has resulted in a fairly major change to the sound, lower bass, better soundstage but possibly a little bit on the bright side.
I have however a couple of questions.
Occasionally on tracks i think I can detect a tiny bit of low end distortion. It might just be my imagination but is there anything that could be causing this by the changes I've made?
Changing the gain to 2x hasn't quite gave me the extra travel on the volume pot I was expecting. I measured the hfe of the BC560's I took out and they were all around 470, the BC327's I used were all 500-505. Would I get more travel on the volume pot if I used lower hfe BC327's (I have matched quads as low as 430)
It's unlikely I'll ever use headphones with the DCG3 (I don't even own a pair) so is there any benefit from running a high BIAS? My DCG3 currently has 7.5 ohm @ 130mA fitted for R10 (I have some 12 ohm Dale CMF60 I can use if lowering the BIAS makes more sense when not using headphones).
Thanks!
I have however a couple of questions.
Occasionally on tracks i think I can detect a tiny bit of low end distortion. It might just be my imagination but is there anything that could be causing this by the changes I've made?
Changing the gain to 2x hasn't quite gave me the extra travel on the volume pot I was expecting. I measured the hfe of the BC560's I took out and they were all around 470, the BC327's I used were all 500-505. Would I get more travel on the volume pot if I used lower hfe BC327's (I have matched quads as low as 430)
It's unlikely I'll ever use headphones with the DCG3 (I don't even own a pair) so is there any benefit from running a high BIAS? My DCG3 currently has 7.5 ohm @ 130mA fitted for R10 (I have some 12 ohm Dale CMF60 I can use if lowering the BIAS makes more sense when not using headphones).
Thanks!
Hfe in the mirror transistors has not to do with the preamp's voltage gain. High Hfe is good. Your description about replacing with BC327s reminds the other reports with the exception that they are usually considered rather on the mellow side when in this circuit.
Maybe the pot's value is straining your source? What value and type pot is there?
You may take it down to 100mA for line level use only.
Maybe the pot's value is straining your source? What value and type pot is there?
You may take it down to 100mA for line level use only.