obsolete
Just started work on my DCG3 build and ran into the BC560c part not available. Obsolete. There are hundreds of PNP BJTs but don't know what to select. And, does that require a change in the BC550c part for matching purposes. Help needed and appreciated.
Thanks,
Don
Just started work on my DCG3 build and ran into the BC560c part not available. Obsolete. There are hundreds of PNP BJTs but don't know what to select. And, does that require a change in the BC550c part for matching purposes. Help needed and appreciated.
Thanks,
Don
Get BC327-40 for Q1 Q2. Tested and recommended. That lone BC550C is for driving the output relay, can have any hfe and has no relation to those signal stage current mirror PNPs.
Salas:
I was going to pair the Ultra BiB 1.3 with the DCG3 to come up with my ultimate pre amp. Then I got to thinking about the DCSTB you did to pair with theDCG3. Is there any reason not to use BiB1.3? Which in your opinion would be the best build? I was planing on using this pre amp to do listening tests with a "few" amp projects. Thanks for your patience with my lack of experience.
Don
I was going to pair the Ultra BiB 1.3 with the DCG3 to come up with my ultimate pre amp. Then I got to thinking about the DCSTB you did to pair with theDCG3. Is there any reason not to use BiB1.3? Which in your opinion would be the best build? I was planing on using this pre amp to do listening tests with a "few" amp projects. Thanks for your patience with my lack of experience.
Don
DCSTB is what was designed together with DCG3 and predates SSLV1.3. Its also sized compatible in dimensions and more thermally efficient because series not shunt. Convenient in smaller boxes. The net subjective result of the duo is certainly tonally neutral and resolving but with a good measure of impact also.
Now if you got full width box space and and you want to use the V1.3 shunts (they need more chassis floor real estate and they give out much more heat than DCSTB) its possible you may enjoy some extra subjective benefits like even better resolve in bass and in low mid and/or little more 3D. A more luxurious type of sound in other words.
On the other hand the net tonal result may acquire more solemnity of manner than neutral. Because the DCG3 is already very good in slam with DCSTB. It may take some experimentation to bring it back neutral like bypassing C2 in the UBiB V1.3 with a 0.1uF MKP, and/or experiment with C6 C7 values & types on the DCG3 itself. Or to match a brighter pot. But I have no recipe to give if you will ever need to enter the tweaks twilight zone. There you walk alone in the valley of elusive tone.
Such things are down to individual taste and system synergy dependent, especially in how they work for particular power amp - speaker - room interfaces.
It will also cost more to build and sink four shunt sections. DCSTB is four sections dual mono already we should not forget.
Now if you got full width box space and and you want to use the V1.3 shunts (they need more chassis floor real estate and they give out much more heat than DCSTB) its possible you may enjoy some extra subjective benefits like even better resolve in bass and in low mid and/or little more 3D. A more luxurious type of sound in other words.
On the other hand the net tonal result may acquire more solemnity of manner than neutral. Because the DCG3 is already very good in slam with DCSTB. It may take some experimentation to bring it back neutral like bypassing C2 in the UBiB V1.3 with a 0.1uF MKP, and/or experiment with C6 C7 values & types on the DCG3 itself. Or to match a brighter pot. But I have no recipe to give if you will ever need to enter the tweaks twilight zone. There you walk alone in the valley of elusive tone.
Such things are down to individual taste and system synergy dependent, especially in how they work for particular power amp - speaker - room interfaces.
It will also cost more to build and sink four shunt sections. DCSTB is four sections dual mono already we should not forget.
In any case when someone decides to go with shunt power supplies he must read post #79:
Few words about power
With UBiB V1.3 the spare current margins for heavy loading headphones could be judged as better at plus 100mA not 50mA as with the BIB V1.1 of the example. More heat.
Few words about power
With UBiB V1.3 the spare current margins for heavy loading headphones could be judged as better at plus 100mA not 50mA as with the BIB V1.1 of the example. More heat.
Few words about power...
Sennheiser HD600 here. No plan to explode it and to blow up my head!
Sennheiser HD600 here. No plan to explode it and to blow up my head!
Classic cans. I have a pair too in my headphones collection. Not the most impressive in bass or stage size but still the most neutral and detailed in the six hundred series. They don't sound distinctly bass shy, mid shouty, or trebly when driven from the DCG3 by the way. They tend to homogenize better there than when driven directly from most source equipment. Mobile phones and PC outputs being their worst direct drive match in my experience. When lower impedance cans sound louder and better fleshed out on such gear.
Sennheiser HD600 Series Showdown and Reviews: HD600 vs. HD650/6XX vs. HD660S
Sennheiser HD600 Series Showdown and Reviews: HD600 vs. HD650/6XX vs. HD660S
Yes, classic. Got them years ago, likely when they came out around 1997. Changed the cable, pads (head and ears) and recently replaced the sole connectors.
Not much aware of the headphone variants, but it looks like most are using 'standard' connectors (?).
Not much aware of the headphone variants, but it looks like most are using 'standard' connectors (?).
Those with removable cable like the 600 series can take any style of amp end connection. There are many third party cable offerings. Because Y separate wired for channels there are four pin XLR balanced configured cables for them as well. Not so on other types with one sided cable of common ground return between channels wire. But balanced cans wiring is only applicable on doubled up PCB XLR DCG3 builds.
Regarding the BC327-40 update in order to replace the 4x BC560C,
Did not find anymore the post explaining how to measure the hfe in order to get pairs (?).
Already went through the whole thread once.
Did not find anymore the post explaining how to measure the hfe in order to get pairs (?).
Already went through the whole thread once.
To measure hfe you either have a DMM that also does so or a semiconductor identifier / tester. There are very many dirt cheap "transistor testers" on eBay and AliExpress capable for the job. They also measure resistance capacitance & inductance in many cases. Absolute accuracy is another matter but alright for matching parts and identifying unknowns or simply testing for good or bad. Either offered as naked board or enclosed in cheap plastic cases they are mainly of this format.
Attachments
Hi Salas,
Was checking the components in the kit for the DCG3 board. Could not find the 2x R3 (150R) resistances. There were however extra 221R and 12R ones. Is it ok to put them in parallel to get around 116R? Or is it better to look for the expected 150R value?
Was checking the components in the kit for the DCG3 board. Could not find the 2x R3 (150R) resistances. There were however extra 221R and 12R ones. Is it ok to put them in parallel to get around 116R? Or is it better to look for the expected 150R value?
This is my doing, in testing the JFETs, the measurements were more in line with using a 221R resistor, so the kits are provided for those.
My bad! 
221R instead of 150R for R3, read that already and it's clearly stated in post #1.
Forgot while checking the components
221R instead of 150R for R3, read that already and it's clearly stated in post #1.
Forgot while checking the components
Good evening Salas,
I wanted to give my pre a better potentiometer than the Alps Blue and I would have chosen what you have recommended several times and that is the one produced by TKD.
To choose the correct value, I would like to understand how the response of the pre varies between the 20k and 50k values, surely you have spoken about it in this trad, but I cannot find it, if you or someone can give me some tips, I would thank him very much.
I wanted to give my pre a better potentiometer than the Alps Blue and I would have chosen what you have recommended several times and that is the one produced by TKD.
To choose the correct value, I would like to understand how the response of the pre varies between the 20k and 50k values, surely you have spoken about it in this trad, but I cannot find it, if you or someone can give me some tips, I would thank him very much.