Have my 4th GB boards tested, installed, measured and singing! Including @felix1024 protection boards, which he helped me out with I was able to KiCAD an opto-AC sense PCB for standby control (as they are designed plug-n-play for the cobra SMPS, which I have also used). @fireanimal 's heatsinks are the icing on the cake too.
Using Hypex soft start, configured with a trigger input controlling a NC relay and front panel NC latching switch in series to make front panel switch and trigger input both take the soft start out of standby. Some reason the Hypex requires a NC switch to operate??? Has bidirectional LED out too so front switch is red on standby/green on. I did notice this soft start gets hot if cycled too quickly, unlike the DIYaudio softstart which seems more forgiving to this. A tiny 5W SMPS runs the speaker protects.
Again, big ups to the team.
(scaling a bit cooked on the REW captures)
Using Hypex soft start, configured with a trigger input controlling a NC relay and front panel NC latching switch in series to make front panel switch and trigger input both take the soft start out of standby. Some reason the Hypex requires a NC switch to operate??? Has bidirectional LED out too so front switch is red on standby/green on. I did notice this soft start gets hot if cycled too quickly, unlike the DIYaudio softstart which seems more forgiving to this. A tiny 5W SMPS runs the speaker protects.
Again, big ups to the team.
(scaling a bit cooked on the REW captures)
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They were i think like 5.9ish volts just real quick to make sure nothing was misbehaving. Along with sweeps. The measurement setup is still lacking. Stuart has given me some nice tips to get noise lower (though I get no noise at speakers anyway). My layout is kind of outside the norm with tx at the back and the IPS's at alternating ends, I encourage anyone starting new to use @danieljw layout he got an excellent virtually zero noise stereo layout (see his youtube wiring vid)
There's at lot of BC550/560 useres here, so I thought this might be the place to aske before using these i my Wolverine build later on.
To the left is an original Fairchild BC550C and to the right "should" be and original Fairchild BC560C, bought from LANGREX on eBay. There's a "B" stamped on the housing on the back of the BC560C... Hfe is around 500-600.
In circuit the BC560 performs good, and I tried swapping to Onsemi BC549C/BC559C and got identical curves from my preamp protobuild.
Can anyone here confirm if the BC560 to the right is original from the picture?
To the left is an original Fairchild BC550C and to the right "should" be and original Fairchild BC560C, bought from LANGREX on eBay. There's a "B" stamped on the housing on the back of the BC560C... Hfe is around 500-600.
In circuit the BC560 performs good, and I tried swapping to Onsemi BC549C/BC559C and got identical curves from my preamp protobuild.
Can anyone here confirm if the BC560 to the right is original from the picture?
@asuslover just to clarify, since there is so many fakes out there. Can I use the 560? The 550 is from a ammo-pack I bought, and test perfect, everything looks original I think, but without a curvetracer I can only test them to some degree.
I wouldn’t use them. I have genuine but you can use the 549/559C. I have also used and tested the bc327/337-40 and they work well.
@fireanimal I've got your email, and we might continue where I left last time regarding these units. I'll get back to you later
Hi guy's,
I hope your builds are going well. 🙂
I recently realized that I have not updated certain aspects of the build guide that relate specifically to the 4th group buy boards (IPS V4.9 & EF3-X V4.2). I apologize for the oversight; I’ve had a lot on.
For now, I've addressed the heatsinks. Please find attached PDF drawings of the heatsinks. Additionally, I’ve uploaded these PDFs to the Dropbox folder.
Thank you for your understanding. If you have any questions or need further information on a particular part of the build guide that requires updating, please let me know.
I hope your builds are going well. 🙂
I recently realized that I have not updated certain aspects of the build guide that relate specifically to the 4th group buy boards (IPS V4.9 & EF3-X V4.2). I apologize for the oversight; I’ve had a lot on.
For now, I've addressed the heatsinks. Please find attached PDF drawings of the heatsinks. Additionally, I’ve uploaded these PDFs to the Dropbox folder.
Thank you for your understanding. If you have any questions or need further information on a particular part of the build guide that requires updating, please let me know.
Finally listened to this amp through some Cerwin Vega D8E's... Very, very nice. Only thing I wish is I should have put it in a bigger chassis with much bigger heat sinks. As long as I keep the glass doors open it doesn't get too warm.
Thanks All.
Scott
Thanks All.
Scott
Attachments
I’m going to be buying some parts from Fireanimal shortly, in the parts will be a couple pair of 2SC4883A and 2SA1859A to be used as drivers over the MJE15032/33. But I was thinking about only building one of the amplifiers using those parts (building 2 amplifiers) and using different drivers for the other amp.
It was already determined that the C4793 and A1837 would be running too close to their limits and that the C5171 and A1930 have a poor SOA. What about 2SC3298B and 2SA1306B pairs? I have a bunch and was curious what people think of these as the SOA graph looks good, they are 100 MHz both the NPN and PNP vs the C4883 being 120 MHz and A1859 only being 60 MHz. I was thinking of building an amp with the 4883/1859 and the other amp with the 3298/1306 and comparing them.
Dan
It was already determined that the C4793 and A1837 would be running too close to their limits and that the C5171 and A1930 have a poor SOA. What about 2SC3298B and 2SA1306B pairs? I have a bunch and was curious what people think of these as the SOA graph looks good, they are 100 MHz both the NPN and PNP vs the C4883 being 120 MHz and A1859 only being 60 MHz. I was thinking of building an amp with the 4883/1859 and the other amp with the 3298/1306 and comparing them.
Dan
If you have some genuine then use them and tell us how they work. I'd use these but these are not available from reliable suppliers any more.
They are indeed genuine, I was just curious what people thought of them and how they’d compare, which pair they’d consider to be better.
Thanks,
Dan
This is an excellent build 👏 👌 🙌 👍
Nice work Mainframe99.