Indeed just a first impression
There'll be lots more I'm afraid (for those who hate long reviews).
With 18-20dB preamps and 2V sources, I've already determined that in my digs, a 91dB speaker is about the limit to have sufficient gain with one stereo F4 also for the audiophile albums that ain't compressed to hell and thus sport a lower median level.
One of my sources can output up to 7V and I've got speakers all the way down to 82.5dB/4 ohms. My most buxom preamp generates 26dB in its highest setting. Once F4 #2 shows up (the shipper returned it to Pass Labs for no good reason so Nelson had to fire it off to Cyprus again), I'll explore some figures of "speaker sensitivity + preamp gain = x setting on the volume with 1 or 2 F4s".
After that, it's massive preamp swapping to see how that affects sonics and feel.
After that, i'ts buffer follower with my 2wpc Yamamoto A-08S and 4-watt Fi 2A3 monos.
Sorry, it'll be looong
There'll be lots more I'm afraid (for those who hate long reviews).
With 18-20dB preamps and 2V sources, I've already determined that in my digs, a 91dB speaker is about the limit to have sufficient gain with one stereo F4 also for the audiophile albums that ain't compressed to hell and thus sport a lower median level.
One of my sources can output up to 7V and I've got speakers all the way down to 82.5dB/4 ohms. My most buxom preamp generates 26dB in its highest setting. Once F4 #2 shows up (the shipper returned it to Pass Labs for no good reason so Nelson had to fire it off to Cyprus again), I'll explore some figures of "speaker sensitivity + preamp gain = x setting on the volume with 1 or 2 F4s".
After that, it's massive preamp swapping to see how that affects sonics and feel.
After that, i'ts buffer follower with my 2wpc Yamamoto A-08S and 4-watt Fi 2A3 monos.
Sorry, it'll be looong
Supratek Cabernet
Srajan
this may be premature but I've already decided that the Cabernet preamp + a pair of F4s should produce sonic Nirvana. Be sure to try yours with the F4s - I'm sure you are planning to - yes?
Ian
Srajan
this may be premature but I've already decided that the Cabernet preamp + a pair of F4s should produce sonic Nirvana. Be sure to try yours with the F4s - I'm sure you are planning to - yes?
Ian
Yes on Cabernet Dual
Mick's nearly done with the upgrade to full 101D/6H30 status which makes my Cab Dual now identical to what's sold presently - mine didn't have the 6H30s and Mick finally convinced me to return the beast to Oz. I'd been so happy, I didn't want to be without it. Once he got it back, he essentially said, "Boy, that's *old* - we've come a long way since, you won't believe the difference."
O-kay, I'm ready to believe. Soon, I take it.
And absoloodely, the Supra and F4 will be the real highlight, I predict. First, the Supra even before the mod was the best pre I've ever heard (not that I've heard all but it's baaad). Second, it's got mondo gain. Put the two together, add the F4 aftern for a hybrid tube front end, transistor tail end three-box amplifier (the Supra's got an outboard tube-rectified, tube regulated power supply) and this combo should drive speakers in the 87-88dB range fine, I'd expect. Perhaps just a skoch lower even in my room.
Then add a second F4 (the Supra's got transformer-coupled true balanced outs), get 100 Nelson watts for current and drive and who knows, mebbe even the very inefficient M&D Rubys and Maximus Monitors can join the party.
Right now they're hanging off 900 watts into 4 ohms of Coda juice and liking it so this will be a real test for the F4 concept (not that it's a really sane proposition but hell, trying doesn't hurt).
Right now things are sounding so good, I'm not that curious anymore to hang the F4 off the Yamamoto. I'll do it, never fear - but for the moment, the old itch for 45s is curiously absent.😀
Mick's nearly done with the upgrade to full 101D/6H30 status which makes my Cab Dual now identical to what's sold presently - mine didn't have the 6H30s and Mick finally convinced me to return the beast to Oz. I'd been so happy, I didn't want to be without it. Once he got it back, he essentially said, "Boy, that's *old* - we've come a long way since, you won't believe the difference."
O-kay, I'm ready to believe. Soon, I take it.
And absoloodely, the Supra and F4 will be the real highlight, I predict. First, the Supra even before the mod was the best pre I've ever heard (not that I've heard all but it's baaad). Second, it's got mondo gain. Put the two together, add the F4 aftern for a hybrid tube front end, transistor tail end three-box amplifier (the Supra's got an outboard tube-rectified, tube regulated power supply) and this combo should drive speakers in the 87-88dB range fine, I'd expect. Perhaps just a skoch lower even in my room.
Then add a second F4 (the Supra's got transformer-coupled true balanced outs), get 100 Nelson watts for current and drive and who knows, mebbe even the very inefficient M&D Rubys and Maximus Monitors can join the party.
Right now they're hanging off 900 watts into 4 ohms of Coda juice and liking it so this will be a real test for the F4 concept (not that it's a really sane proposition but hell, trying doesn't hurt).
Right now things are sounding so good, I'm not that curious anymore to hang the F4 off the Yamamoto. I'll do it, never fear - but for the moment, the old itch for 45s is curiously absent.😀
Srajan,
Welcomed to DIYaudio. Great to see you have join this thread. I always enjoy your reviews at 6moons especially when you do equipment from designers I know.
Keep up those excellent reviews… looking forward to read about the next installment of the F4 saga.
Best regards
😎
Welcomed to DIYaudio. Great to see you have join this thread. I always enjoy your reviews at 6moons especially when you do equipment from designers I know.
Keep up those excellent reviews… looking forward to read about the next installment of the F4 saga.
Best regards
😎
Srajan is still waiting for his second F4 so that he can try the mono configurations.
Unfortunately only one of the two that I shipped got through.
Fortunately the second unit bounced back to me, so we'll try again.
😎
Unfortunately only one of the two that I shipped got through.
Fortunately the second unit bounced back to me, so we'll try again.
😎
Nelson Pass said:
next time feel free to write mine as bouncing address
it doesn't matter what's in box
Member
Joined 2002
has anyone gotten thier F4 up and running using Peter Daniel's PSU boards? Just curious which final configuration you settled on...
Member
Joined 2002
luvdunhill said:
I should have mine up when my transformer arrives, i need to order a few parts still. I opted out for peter's psu boards and bought a pair of Brian GT psu boards for mine and another member's. Im building the CRC psu.
Jase
Jase,
Those sinks look plenty big and very nice I'm very jealous
I should have gotten in on that old group buy!
Srajan,
I don't think that anyone at DIY Audio will complain if you write as much F4 info as possible!!
Those sinks look plenty big and very nice I'm very jealous
I should have gotten in on that old group buy!
Srajan,
I don't think that anyone at DIY Audio will complain if you write as much F4 info as possible!!
Member
Joined 2002
Variac said:Jase,
Those sinks look plenty big and very nice I'm very jealous
I should have gotten in on that old group buy!
What group buy ? BrianGT got these for me for my Birthday, i was at his house 3 days after my b-day and he had them for me 🙂
Jase
Jason,
Are those sinks made from one piece? On the pic I thought it could also be two smaller sinks bolted together with a black-colored plate on the inside.
If yes, please post a link for some serious sink shopping. Thx.
Are those sinks made from one piece? On the pic I thought it could also be two smaller sinks bolted together with a black-colored plate on the inside.
If yes, please post a link for some serious sink shopping. Thx.
Member
Joined 2002
DocLorren said:
It is Actually 2 heat sinks, one per side, if i remember it is 12" x 11" piece. They are heavy 🙂
Ooh, sexy!
Any idea where to purchase this kind (better than 0.3K/W; what are the actual specs for these?) of sink in Europe (not conrad.de or conrad.nl, for sure)? Thx.
Any idea where to purchase this kind (better than 0.3K/W; what are the actual specs for these?) of sink in Europe (not conrad.de or conrad.nl, for sure)? Thx.
ah, okay, perhaps this is a better question. On NP's schematic, he lists the diodes as 35A / 200V... Is the 35A rating the forward current (If) or the non-repetitive forward current (Ifsm). Really, either way, how is this possible with a 2.5A slow-blo fuse?
Thank you!
Thank you!
luvdunhill said:
That is the manufacturer's rating - this is a typical power rectifier
bridge. Of course you can run a rugged bridge at lower than
rated currents.
😎
Nelson Pass said:
NP:
Thanks for the reply! So, with the recommended fuse for the F4, what are the greatest currents that the bridge could see? I guess it would be the maximum that the slo-blo fuse would let in before blowing, huh 😉 Just curious I guess.
Also, what do you maximum working voltage do you recommend for the 220uF capacitors? perhaps 50 VDC?