Thanks for the quick reply
Right O, two SMPS1200s it is, top of the list after work tomorrow. Glad to see I do not need the Hypex SMPS cable kit, based on the manual
Ha, ha, what is "wide curve around?" ...Having to spend as much $$$ to interface this kit to your PC as much as the kit costed itself? (yes, I am expressing some frustration that I have personally encountered here.) ...Or are we talking about a soundstage that is a very wide curve but no depth?
I will look into your suggestions. They seem less frustrating
No doubts, two SMPS1200A400 connected as described in manual, best 3D imaging.
Right O, two SMPS1200s it is, top of the list after work tomorrow. Glad to see I do not need the Hypex SMPS cable kit, based on the manual
Sabre DAC - wide curve around, heard many, sold all of them. Discrete R-2R or AD1955 many in parallel that's the way.
Ha, ha, what is "wide curve around?" ...Having to spend as much $$$ to interface this kit to your PC as much as the kit costed itself?
(yes, I am expressing some frustration that I have personally encountered here.) ...Or are we talking about a soundstage that is a very wide curve but no depth? I will look into your suggestions.
They seem less frustrating 
Farewell
I agree CFA rules, all amps First One bettered were VFA.
Guys, very sad day for DIY audio, I see our member Esperado is banned, lots of knowledge he gave generously to this community will never be forgotten.. stay well my dear friend.
Best regards, L.C.
I'm sure you will agree, CFA rulez
I agree CFA rules, all amps First One bettered were VFA.
Guys, very sad day for DIY audio, I see our member Esperado is banned, lots of knowledge he gave generously to this community will never be forgotten.. stay well my dear friend.
Best regards, L.C.
SMPS ordered...
After three days of shoveling large amounts of snow...
...Got two SMPS ordered from Hypex. I ended up getting the extra wire kits also, as they had the connectors on them. I like the idea of keeping everything factory in case Murphy's Law kicks in
I know Cresnet has a SMPS suitable for this Amp module also. I personally am not courageous or knowledgeable enough in how a PSU design effects the performance of a given amp circuit. Which is why I went with the currently well documented Hypex. But it does cost $$$, boy does it cost.
Cresnet's SMPS costs quite a bit less, so it may be a more attractive option for the braver of You electrical adventurers out there.
Thanks for the offer Cresnet, I hope You find someone to try out your design, and I hope that someone will post here their impressions. It would be nice to find a more cost effective SMPS for these Amp modules.
After three days of shoveling large amounts of snow...
...Got two SMPS ordered from Hypex. I ended up getting the extra wire kits also, as they had the connectors on them. I like the idea of keeping everything factory in case Murphy's Law kicks in
I know Cresnet has a SMPS suitable for this Amp module also. I personally am not courageous or knowledgeable enough in how a PSU design effects the performance of a given amp circuit. Which is why I went with the currently well documented Hypex. But it does cost $$$, boy does it cost.
Cresnet's SMPS costs quite a bit less, so it may be a more attractive option for the braver of You electrical adventurers out there. Thanks for the offer Cresnet, I hope You find someone to try out your design, and I hope that someone will post here their impressions. It would be nice to find a more cost effective SMPS for these Amp modules.
diyAudio Chassis possibility...
diyAudio member 6L6 informed me on the Chassis Discussion thread, that the Dissipante 3U 300 mm chassis is more then adequate for a stereo build of this amp.
Dissipante 3U – diyAudio Store (BETA)
He suggested that one could maybe go with the Dissipante 4U 300 mm and install more modules (4 channel), if "assuming you don't have very inefficient speakers and like to listen really loud..." The latter half being a possible issue for me. He suggested two 3U 300 mm chassis would be better for a four channel build...
http://www.diyaudio.com/forums/diyaudio-store/221218-chassis-discussion-36.html#post4599850
So that is what I will go with. I think it will look cooler anyway.
The diyAudio store also will CNC custom cutouts for the front and back plates of their chassis for reasonable $$, so I need to get hardware I want and draft up a cutout plan. They also offer full color digital printing on the front plates. The diyAudio store has come a long way this year.
So next up for me, is hardware: binding posts, EMI IEC, RCA's, etc...
diyAudio member 6L6 informed me on the Chassis Discussion thread, that the Dissipante 3U 300 mm chassis is more then adequate for a stereo build of this amp.
Dissipante 3U – diyAudio Store (BETA)
He suggested that one could maybe go with the Dissipante 4U 300 mm and install more modules (4 channel), if "assuming you don't have very inefficient speakers and like to listen really loud..." The latter half being a possible issue for me.
He suggested two 3U 300 mm chassis would be better for a four channel build...http://www.diyaudio.com/forums/diyaudio-store/221218-chassis-discussion-36.html#post4599850
So that is what I will go with. I think it will look cooler anyway.
The diyAudio store also will CNC custom cutouts for the front and back plates of their chassis for reasonable $$, so I need to get hardware I want and draft up a cutout plan. They also offer full color digital printing on the front plates. The diyAudio store has come a long way this year.
So next up for me, is hardware: binding posts, EMI IEC, RCA's, etc...
All the best to our fellow member
I know Cresnet has a SMPS suitable for this Amp module also. I personally am not courageous or knowledgeable enough in how a PSU design effects the performance of a given amp circuit. Which is why I went with the currently well documented Hypex. But it does cost $$$, boy does it cost.
Swapping the output PS caps for better quality ones (and the same ratings) is an easy and rewarding move. Easier still: parallel 1uF red Wimas to the stock output caps (Samwha) ... I swear my DIY VSSA sounds better now.
I guess swapping also the main "input" cap (usually 400V; sorry for the nomenclature) may also also be worthwile, but at higher cost.
SMPS1200 has 100 kHz/50 % duty cycle transfer over main HF transformer, AC rectifying with mosfets - getting 200 kHz pulsed DC before smoothing with onboard 660 uF on each rail. Mundorf elcos with several strategical 1 uF decouplers on First One module serves so well that recapping on SMPS1200 is practically worthless.
Ha, ha, what is "wide curve around?" ...Having to spend as much $$$ to interface this kit to your PC as much as the kit costed itself?
I will look into your suggestions.
Detour to avoid Sabre DAC, my sincere advice.
Thank you LC. We were talking about modifying cheaper SMPS offers.
(without having any knowledge, that is
)Perhaps I should have been clearer.
Cheers,
M.
No, no, you were very clear about VSSA-SMPS recapping benefit. First One, having much higher PSRR, is not so sensitive to any kind of rail's ripple, so recapping would not bring much, energy storage at same uF value is the same. Lower ESR is desired because of faster transient response, so high performace SMPS's primary elcos like Panasonic EE series would be always beneficial.
Thank you LC. We were talking about modifying cheaper SMPS offers.
(without having any knowledge, that is
I have to wonder if the cheaper SMPS ends up being cheaper after investing the money and time into the mods. High End Caps can get pretty $$$.
Glad I want with the Hypex SMPS
Yes, I am questioning if the Buffalo DAC is worth my time. Long term, many other users of various designs (both commercial and diy) with the Sabre DAC never attain a compromised balance of what they are looking for and gave up on them. The attraction to this chip is the multi-channel capacity, but even that it not so easy to obtain with the Twisted Pair kit. This, of course, is my personal experience. I am not an electrical designer and avoid surface mount soldering.
On the electronics side, I like mixing and matching "proven" kits. The Discreet 2-R2 seems interesting, as it is a modular approach like the Buffalo. More research will reveal how well this can be implemented (paralleled) for multi-channel and different output stage kits. Same goes for the boards using the AD1955 also. This, of course is outside the scope of this thread, so I will leave it at that. I will be sure to let You know which DAC sounds good with the First One, when I find or build it...Lots of reading and research to do...
Allen
Hi Lazy Cat.
On Friday I received the FO 1.4M modules. I created a test setup and did some listening tests, which are good.
Anyway, I checked VAS current and output MOSFETs current. My supply voltage is +-60V. Default setting from You was:
- MOSFETs cca 350mA (both modules)
- VAS (2x2 modules) - cca 25 to 35mA
- output DC - less than 30mV
I measured after the cooler got warm
1)
While MOSFETs current was quite stable depending on their temperature, the VAS current seemed to change quite much. Is this observation correct?
2)
Since the default values seemed to high (manual says 280mA MOSFETs, 18mA VAS), I decreased them to 300mA and 20mA respectively. Is it OK?
3)
Are the current values expceted to be dependent on the power supply voltage? If yes, how?
Thanks.
On Friday I received the FO 1.4M modules. I created a test setup and did some listening tests, which are good.
Anyway, I checked VAS current and output MOSFETs current. My supply voltage is +-60V. Default setting from You was:
- MOSFETs cca 350mA (both modules)
- VAS (2x2 modules) - cca 25 to 35mA
- output DC - less than 30mV
I measured after the cooler got warm
1)
While MOSFETs current was quite stable depending on their temperature, the VAS current seemed to change quite much. Is this observation correct?
2)
Since the default values seemed to high (manual says 280mA MOSFETs, 18mA VAS), I decreased them to 300mA and 20mA respectively. Is it OK?
3)
Are the current values expceted to be dependent on the power supply voltage? If yes, how?
Thanks.
Hi Pax1
No problem with initial high mA since production calibration is done on 23°C plate to reference values specified. When warm these goes up, so as suggested by manual they have to be re-checked at warm steady conditions ie. 40-45°C heatsink temperature. 20 mA/300 mA is OK if your heatsink is 0,5°K/W or less, if not, set 18 mA/280 mA as specified per manual. VAS bias is mainly temperature dependant, output bias is self tracking since output mosfet's bias current is set at neutral tempco.
Any pics of test setup?
Regards, L.C.
No problem with initial high mA since production calibration is done on 23°C plate to reference values specified. When warm these goes up, so as suggested by manual they have to be re-checked at warm steady conditions ie. 40-45°C heatsink temperature. 20 mA/300 mA is OK if your heatsink is 0,5°K/W or less, if not, set 18 mA/280 mA as specified per manual. VAS bias is mainly temperature dependant, output bias is self tracking since output mosfet's bias current is set at neutral tempco.
Any pics of test setup?
Regards, L.C.
OK, there should be no his or hum with SMPS1200, please make connections and measurements as described in manuals.