I use the same components and transformer and the OP's measurements are identical to mine, no worries.
not really a tough audience mate, its just that these and any other question you can think of wrt this and other pass amps has already been asked and covered over and over, as well as being pretty well covered in the original article. so starting a new thread for every new question just takes up space for no good reason. first search, then pose a question in one of the related threads, or if its a particularly unique request (which this is not), perhaps a new thread.
oh and to know what they are talking about wrt 42, you must already know the answers to life the universe and everything
oh and to know what they are talking about wrt 42, you must already know the answers to life the universe and everything
Looks to me that you do not have a 115:18+18Vac transformer.
What is the open circuit voltage of the transformer? measure the Primary voltage at the same time.
I think you have a 15Vac transformer that as with all transformers measures high when unloaded and varies with mains/primary voltage.
What is the open circuit voltage of the transformer? measure the Primary voltage at the same time.
I think you have a 15Vac transformer that as with all transformers measures high when unloaded and varies with mains/primary voltage.
ZM is dumbwarped
if you ask me - case closed , court dismissed
CanAman ....... next question , please 🙂
Last edited:
there are several reports on the f5 thread , even a whole thread somewhere on diyaudio about the antecs reading low .
btw , mine's a 500va .
cheers Woody
btw , mine's a 500va .
cheers Woody
I doubt that.
It is far more likely that the Antek data is being miss-interpreted by Members who should know better, before complaining about a problem that does not exist.
Nikon....
That would be my guess, too.....
42, as in the ultimate solution to the creation of the universe and everything else.
That would be my guess, too.....
42, as in the ultimate solution to the creation of the universe and everything else.
a 15V trafo with good 'regulation' could easily be labelled as 18V, with low regulation, and still meet the specs
its just not intended to be loaded this hard
the other day I was surpriced to find how much regulation percentage vary, within the same size trafo
from no regulation up to about 20% regulation, and almost everything in between
small trafos though
you got that back to front.
And neither meets specification.
115:15Vac 5% regulation 200VA, specifies the transformer for voltage and current.
115:18Vac 5.5% regulation 180VA, specifies this smaller transformer for voltage and current.
They cannot be mistaken for each other !!!!
hey, Andrew, you are not reading my words
I said, if the 18V is factory specced to have NO regulation, then it meets the factory specs
and a 15V WITH good regulation specs may end up the same
that is, under hard load
I'm not talking about being mistaken for each other
but about the same trafo deliberately labelled to meet diffferent specs
depends on the regulation requested, and expected load
I said, if the 18V is factory specced to have NO regulation, then it meets the factory specs
and a 15V WITH good regulation specs may end up the same
that is, under hard load
I'm not talking about being mistaken for each other
but about the same trafo deliberately labelled to meet diffferent specs
depends on the regulation requested, and expected load
I dug up the Antek specs for my 4218 transformer (dual 18 v secondaries, 400VA). Here's the Antek loading spec:
---------------
Load Test (operation test):
TEST CONDITION: Input 120VAC 60Hz to the primary coils (in
parallel), Output 1 and Output 2 in parallel to load, and measure voltage
and current at different load levels.
Voltage output Current output Power output
18.9V 0.0A 0W
18.6V 7.5A 140W
18.3V 22.2 406W
----------------
It would seem I'm seeing a lot more "power supply sag" with light loading--I have only 18.0 VAC on the secondaries, at 2.6A per rail. Unloaded, I'm seeing 18.5 VAC. That's a 0.5V sag, at only about 12% rated max output load.
Tomorrow I'll pull the transformer and run it through a series of load tests in my power department development lab at work. We design, develop and build large (32-megawatt, $190m US) UHF phased-array radars, and have a pretty good engineering staff (250+) to include about 15 power/distribution engineers. Putting the Antek thru it's paces during a coffee break should be revealing. Besides loading, we'll also take some flux and saturation hall-sensor measurements on the core. (This may become more of an post-moretem autopsy, then a loading test!)
Based upon factual inputs I received in this thread from Woody1911a1, 6L6, and Westend, it would appear my Antek transformer is a "solid underperformer". If that's the case, I hope to resolve it with Antek, and probably go for a 600VA Antek (like 6L6 is using), just because......
In the meantime, I'm really enjoying the marvelous soundstage of my F5--and that's really what's it's all about. In fact, if earlier threads and schematics didn't stress a 24V per rail PSU, and 24v rails in the amp, probably would not be pursuing this as an "intellectual exercise" any further. (But it's all in search of the "Perfect 42"...... Right, Zen Mod?) 😀
Thanks, all.......... and in particular for the factual data from other F5 users..... confirmed what I had initially suspected.
Ken
---------------
Load Test (operation test):
TEST CONDITION: Input 120VAC 60Hz to the primary coils (in
parallel), Output 1 and Output 2 in parallel to load, and measure voltage
and current at different load levels.
Voltage output Current output Power output
18.9V 0.0A 0W
18.6V 7.5A 140W
18.3V 22.2 406W
----------------
It would seem I'm seeing a lot more "power supply sag" with light loading--I have only 18.0 VAC on the secondaries, at 2.6A per rail. Unloaded, I'm seeing 18.5 VAC. That's a 0.5V sag, at only about 12% rated max output load.
Tomorrow I'll pull the transformer and run it through a series of load tests in my power department development lab at work. We design, develop and build large (32-megawatt, $190m US) UHF phased-array radars, and have a pretty good engineering staff (250+) to include about 15 power/distribution engineers. Putting the Antek thru it's paces during a coffee break should be revealing. Besides loading, we'll also take some flux and saturation hall-sensor measurements on the core. (This may become more of an post-moretem autopsy, then a loading test!)
Based upon factual inputs I received in this thread from Woody1911a1, 6L6, and Westend, it would appear my Antek transformer is a "solid underperformer". If that's the case, I hope to resolve it with Antek, and probably go for a 600VA Antek (like 6L6 is using), just because......
In the meantime, I'm really enjoying the marvelous soundstage of my F5--and that's really what's it's all about. In fact, if earlier threads and schematics didn't stress a 24V per rail PSU, and 24v rails in the amp, probably would not be pursuing this as an "intellectual exercise" any further. (But it's all in search of the "Perfect 42"...... Right, Zen Mod?) 😀
Thanks, all.......... and in particular for the factual data from other F5 users..... confirmed what I had initially suspected.
Ken
wrong ;
42 is already perfect .......
one important thing - what's projected mains voltage for your Antek drek , and what's voltage in your mains , while you are taking measurement ?
Tsk-tsk, Zen Mod..... 
Only a "greenhorn" would forget to measure actual line voltage during a power transformer test. 🙂
See my posting #12, this thread: "Also measured each secondary at 18 VAC with a 2.6 amp load on each PSU rail. That was measured with our normal 119 VAC primary (line) voltage here."
Thanks!
Ken Mod (soon to be my new diyaudio screen name)
Only a "greenhorn" would forget to measure actual line voltage during a power transformer test. 🙂
See my posting #12, this thread: "Also measured each secondary at 18 VAC with a 2.6 amp load on each PSU rail. That was measured with our normal 119 VAC primary (line) voltage here."
Thanks!
Ken Mod (soon to be my new diyaudio screen name)
OK I'm 4-eyes , and you're slow in revealing all necessary data when needed
Attachments
.....and you're slow in revealing all necessary data when needed
Heck, ZM--at MY AGE, sometimes I'm even slow in revealing TO MYSELF where I last left my car keys.......!
ur crazy 'smilies' always make me smile 
hey, CanAm
do not forget what was also said
with lowish voltage you have the major opportunity to increase bias
which could be an advantage with lower impedance speakers
its been debated unendlessly that a standard adjusted F5 will half its classA output to 12watt into 4ohm
if you have say 20watt classA into 8ohm, you could make it maybe 18watt into 4ohm, by increasing bias
your heatsinks are surely big enough to do that
that way you could turn the 'voltage sag' to your advantage, so to speak
hey, CanAm
do not forget what was also said
with lowish voltage you have the major opportunity to increase bias
which could be an advantage with lower impedance speakers
its been debated unendlessly that a standard adjusted F5 will half its classA output to 12watt into 4ohm
if you have say 20watt classA into 8ohm, you could make it maybe 18watt into 4ohm, by increasing bias
your heatsinks are surely big enough to do that
that way you could turn the 'voltage sag' to your advantage, so to speak
Heck, ZM--at MY AGE, sometimes I'm even slow in revealing TO MYSELF where I last left my car keys.......!
worse if you forget where you left your car
- Status
- Not open for further replies.