How far off is it?I guess I join in ..... I almost finish with the darling amp but the B+ Don’t match ...Waiting on some resistor
If your speakers are 16 ohms and sensitive, then it could work. I would estimate that you'd need 16 ohm 98+dB sensitive speakers for it to make much sense.I have parts for but not sure if its worth it as my speakers are 16 ohm and the sony output transformers are 8 ohm
If the output transformer has a 600 ohm tap and an 8 ohm tap, then I might go looking for a different transformer for a Darling project. If you use the 8 ohm tap, there will be tons of copper on the secondary that's unused, and in my experience this will seriously degrade the performance of the transformer. The 8 ohm tap on 32 ohm headphones will have plenty of power for most headphones. 750mW into 8 ohms is about 2.5V RMS, and 2.5V RMS into 32 ohms is 180mW. That's a lot of power for what is likely a very sensitive headphone.I did think about using the 600 ohm tap for headphones but my headphones are 32 ohm so not sure that woukd work out that well either.
The B+ 380 vdcHow far off is it?
Are you using the 110V or 121V primary tap?The B+ 380 vdc
Are you using the 110V or 121V primary tap?
Got the iron (actually ended up with a complete second set thanks to a generous donation from @electrovice) - now to figure out the chassis layout.
This is the layout I'm tentatively going with (still need to CAD - e.g. Cardboard Aided Design - the layout to ensure there's sufficient spacing between components) - dimensions are 12.25" x 9" on a2mm3mm thick aluminum plate:
View attachment 20455
Upper left corner is 6CA4 and 20uF oil cap. PT in the center. 40uF and 20uF oil caps in the upper right corner. 156R choke in front (below deck) of the PT. Output transformers underneath the deck and rotated 90 degrees (and offset) from the choke. RCAs are placed next to the 6SF5 driver tubes in the interests of low noise.
The top plate will be dadoed into the wooden base via a 0.25" deep slot (so once it is in, it's in). Power inlet and binding posts will be on a sub-panel rabbeted and screwed into the back of the base. Bottom panel will be rabbeted and screwed into the bottom of the base.
Also, I'll finally be able to use some of those nifty EF Johnson octal tubes that @Redboy turned me on to (thanks, Nate!).
(if anyone wants the .FPD files once I've verified the layout, send me your email address in PM and I'll fire 'em off to you)
Cardboard Aided Design checked out (choke and outputs will be below decks) , so now to order the panels. Given we're ground zero in the COVID-19 outbreak in the USA, I figure I'll have lots of 'at home' time in the next few weeks.
View attachment 20544
-D
Cardboard Aided Design checked out (choke and outputs will be below decks) , so now to order the panels. Given we're ground zero in the COVID-19 outbreak in the USA, I figure I'll have lots of 'at home' time in the next few weeks.
View attachment 20544
-D
Thank you!Looking good @Thermionics ! Any hints on the base wood species/finish?
Thank you - I'm waiting for some 270k KOA-Speer resistors which are coming from Canada (Mouser was out), so I'm stuck. Also, I need to build a chassis, but we're sorta in a quarantine lockdown in the state of Washington right now, so I'm not sure I'll be getting over to my brother-in-law's house (he's the finish carpenter / cabinetmaker in the family) any time soon.Looks like progress to me.
Very nice.