Very impressive how much work and expertise goes into creating this design. A big thank you to every one who is contributing!
building and listening to the wolverine-precision ef3-4 combination will be something special.
Stuart do you think there will be a future spooky ips option or has this idea been dropped?
building and listening to the wolverine-precision ef3-4 combination will be something special.
Stuart do you think there will be a future spooky ips option or has this idea been dropped?
Hi Nikos,
No, we will offer 3 colours as advised previously. The only reason I said blue and small batch was because we made a few very minor tweaks between prototype 3 of the EF3-3 boards and the final version. This will give us an opportunity to confirm the gerbers are now 100% correct for all future EF3-3 batchs.
It will also be the first batch of the EF3-4 boards ever made. Thimios will build and check everything is in order.
So don't worry we won't be skimping on the EU distribution.
The idea has definitely not been dropped, but I think the design team will want a extended break once this project reaches the distribution cycle. We have been at it for quite some time.
We will probably be busy for a few months helping new members and updating documentation etc before we start thinking about the next IPS.
The illustrated build guild currently stands at 27 pages.
The EF3 3 pair board handles 4 ohm loads with no problem. I have thoroughly tested 4 boards using 4 different output devices to establish this. As far as power goes, I have observed during testing 288W into 4 ohm using 150W outputs with 57v rails. My speakers are not what you would consider to be efficient. They are rated at 4 ohm nominal and the Wolverine has no problem powering them well beyond where you would typically listen to music.
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The rule of thumb that has been going around this forum for years is to add up the total watt rating for all of the output devices and divide by four for maximum safe output, or divide by 5 for a little extra margin for safety so 6 x 150W output devices is 900 / 4 = 225W safe output. Four output pairs would increase the safe output to 300W.
Hi Jwihelm
Which devices are you referring to with 150w output. Based on the specifications of each one?
NJW0281 2SC5200 JW3281??
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The 4 pair board is 347mm long, which essentially means the entire usable area of a 400mm heat sink will be used. Making the decision between the 3 pair or 4 pair configuration gets down to what your goals are. It's easy enough to use 200W outputs on the 3 pair board and you'll have a very powerful amp capable of doing whatever you want within reason. If you're intrigued with the thought of a bi-amp configuration for your speakers, as I am, then the 3 pair is the only way to go, if you want to use a single chassis. I simply mounted the boards perpendicular to the heat sink. Using the 5U box provides just enough room to accommodate the 3 pair boards, speaker protection, PSU, etc.
I'm hoping to build a lower-powered EF3-3 version in a 3U / 300mm chassis for my parents. The chassis would need to house a preamp as well (probably a BA2018, but maybe just a simple diamond buffer instead). I'm hoping that with 50V rails the 3U heatsinks will be adequate. My parents tend to listen to music all day long, so this project may be doomed from the very get-go. Their speakers are about 87 dB / 1 watt efficient.
SRMcGee, the 3U300m at 50V will be more than adequate and barely warm at all day listening levels with those speakers. A teenage party might be quite a lot warmer. Those 3U heatsinks combined with the case ventilation are very effective. Its just that some of us need/want the bigger case to stuff more things inside.
Johno:
Thanks - that makes perfect sense to me. My parents are 88 and 85 and tend to rock out with classical music, mostly quartets and solo strings and piano. Not so much ska or hip hop. And while their hearing acuity has unquestionably suffered, they don't listen at earth-shattering volumes. They will undoubtedly prefer a somewhat sleeker 3U chassis over the 4U and 5U competitors.
Regards,
Scott
Thanks - that makes perfect sense to me. My parents are 88 and 85 and tend to rock out with classical music, mostly quartets and solo strings and piano. Not so much ska or hip hop. And while their hearing acuity has unquestionably suffered, they don't listen at earth-shattering volumes. They will undoubtedly prefer a somewhat sleeker 3U chassis over the 4U and 5U competitors.
Regards,
Scott
Kuddos to all involved with the development of Wolverine! Its been a long road but looks to be well worth the time and effort put in.
I have a similar scaling down question as SRMcGEE. Could this work with 2 output pairs per channel? I checked my stash and have 4 pairs of 2SC3264/2SA1295 Sanken BJT’s.
I have a similar scaling down question as SRMcGEE. Could this work with 2 output pairs per channel? I checked my stash and have 4 pairs of 2SC3264/2SA1295 Sanken BJT’s.
I recommend that you save your Sankens until you have enough to complete the 3 pair, plus a couple for contingency
. You can build the Wolverine using other 200W outputs, if that's what the objective is, and you will not be disappointed. I'm still listening to the board with 150W outputs and it just delivers...
. You can build the Wolverine using other 200W outputs, if that's what the objective is, and you will not be disappointed. I'm still listening to the board with 150W outputs and it just delivers...