I could use a word of advice please.
you know how it goes with the DIY "evolution"; one develops new tastes and ends up looking at his stock of parts and scratching head
.
Imagine the following unlikely system: after experiencing a well tuned distributed bass at Earl Geddes's place, I decided to add two 12" subs driven by Dclass mono amps. the problem is that I now turned my 85L Elsinore speakers into mid/high units; and they do a lovely job at that (!), at the same time presenting an easy 8ohm load to an Aleph30 driven by an AlephP. the source is balanced, and my wife is not happy! (saving bold characters for what matters
).
Here comes my question: I will be looking to replace Elsinores with something a bit smaller and hopefully even better at midrange/vocal reproduction. Looking at alternatives I seem to be developing a taste for 4ohm speakers, and could use a bit more power too (probably 50w classA would do it; 100w would be better!).
originally I was planning to convert my aleph30 into a balanced F4 mono block at +-24V rails and just add another one, but 4ohm load would present a problem there, right?
running F4 modules in parallel for more current does not jive well with the balanced input though.
so after all, an alephX (or F5X), would have been a better choice??? (which would make converting my Aleph30 w/ 25V rails not possible (i.e. a new Xformer and package may be required 🙁).
What do you gents think? please share>>
you know how it goes with the DIY "evolution"; one develops new tastes and ends up looking at his stock of parts and scratching head
.Imagine the following unlikely system: after experiencing a well tuned distributed bass at Earl Geddes's place, I decided to add two 12" subs driven by Dclass mono amps. the problem is that I now turned my 85L Elsinore speakers into mid/high units; and they do a lovely job at that (!), at the same time presenting an easy 8ohm load to an Aleph30 driven by an AlephP. the source is balanced, and my wife is not happy! (saving bold characters for what matters
).Here comes my question: I will be looking to replace Elsinores with something a bit smaller and hopefully even better at midrange/vocal reproduction. Looking at alternatives I seem to be developing a taste for 4ohm speakers, and could use a bit more power too (probably 50w classA would do it; 100w would be better!).
originally I was planning to convert my aleph30 into a balanced F4 mono block at +-24V rails and just add another one, but 4ohm load would present a problem there, right?
running F4 modules in parallel for more current does not jive well with the balanced input though.
so after all, an alephX (or F5X), would have been a better choice??? (which would make converting my Aleph30 w/ 25V rails not possible (i.e. a new Xformer and package may be required 🙁).
What do you gents think? please share>>
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I think the F4 balanced has a reasonable shot at 4 ohms.
The A75 fills the bill pretty nicely, but is more complex.
😎
The A75 fills the bill pretty nicely, but is more complex.
😎
wow, an answer straight from the top and this quickly. what a start for a new thread. thanks Papa!
now, you know if you say: "it has a chance" that means it will be tested in my home 🙂! I have the parts for it, and my only concern was charring the sillicone.
p.s A75? hmm, never even considered it since it sort of fell into the "history" drawer. (plus, I am biased for amps recognized for their softer side and (shell I use the word): "warmer" vocal reproduction). but will keep it in mind in case F4 goes up in flames (come to think of it: not sure if a smiley would be appropriate here).
now, you know if you say: "it has a chance" that means it will be tested in my home 🙂! I have the parts for it, and my only concern was charring the sillicone.
p.s A75? hmm, never even considered it since it sort of fell into the "history" drawer. (plus, I am biased for amps recognized for their softer side and (shell I use the word): "warmer" vocal reproduction). but will keep it in mind in case F4 goes up in flames (come to think of it: not sure if a smiley would be appropriate here).
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start with 3-deep , and just add until you're happy
though , in that case be prepared for plenty of heat ..... price of happiness
due time , you'll search to improve (on ) Aleph P ; start with proper shunt supply per channel
(just to add answer straight from the bottom
)
though , in that case be prepared for plenty of heat ..... price of happiness
due time , you'll search to improve (on ) Aleph P ; start with proper shunt supply per channel
(just to add answer straight from the bottom
)Thanks ZM. will do 😀.
I use fan cooled 9inch long hsinks and so far so good for up to 300W dissipation (over that not tested yet). I hope that will be enough per channel.
p.s. as for the AlephP regulator: I know; Papa does not have much patience for developing power sections and prefers to spend time on the (amp) meat. I keep Salas or similar reg in mind.
I use fan cooled 9inch long hsinks and so far so good for up to 300W dissipation (over that not tested yet). I hope that will be enough per channel.
p.s. as for the AlephP regulator: I know; Papa does not have much patience for developing power sections and prefers to spend time on the (amp) meat. I keep Salas or similar reg in mind.
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it'll be overkill
though , don't expect massive Klunk! feedin' da boomers , so you can ease there substantially
there's "even" properly made Quad 405 ruling ..... except if you're conducting very nervous welding session with it
edit - in some parts of world , it's simply rude using heatsinks shorter than 10" 😉
though , don't expect massive Klunk! feedin' da boomers , so you can ease there substantially
there's "even" properly made Quad 405 ruling ..... except if you're conducting very nervous welding session with it
edit - in some parts of world , it's simply rude using heatsinks shorter than 10" 😉
for the power and SPL level: point taken, I will still watch the bottom line on speaker sensitivity (probably 90dB/wm), should be enough with the subs helping the bottom end.
for the heat: I probably could not do better than 280-300W anyways since i am sticking with the truly quiet fan (Noctua; nothing else works at this time).
but what do you say of Papa blowing the dust off of A75? will make me go back and read it now? (I only remember it used a voltage doubler for the FE etc.). still, I think has no chance before I tried bal F4 first
.
for the heat: I probably could not do better than 280-300W anyways since i am sticking with the truly quiet fan (Noctua; nothing else works at this time).
but what do you say of Papa blowing the dust off of A75? will make me go back and read it now? (I only remember it used a voltage doubler for the FE etc.). still, I think has no chance before I tried bal F4 first
.
go back and read it - there is enough material for brainjoy for at least two week evenings
in a meantime - build F4s
in a meantime - build F4s
As for Aleph P 1.0 or BOSOZ or balanced Zen Linestage; more current, like 80-100mA/leg, higher supply voltage, and output loading, will make them shine also. You might try SemiSouth R550 rather than the 610 or 244 😉
The F4 or variations of BA-2 OS, as already suggested, would be good. The F.E. becomes the more important circuit topology of the amp then. Balanced or bridged outputs are better at 8 ohm loads and higher, mostly because it's similar to two parallel amps driving 4 ohms each. An output stage with gain and high current capability is what you'll end up with most likely IMO. Finding so many matched complimentary pairs can be frustrating and expensive 🙁
The F4 or variations of BA-2 OS, as already suggested, would be good. The F.E. becomes the more important circuit topology of the amp then. Balanced or bridged outputs are better at 8 ohm loads and higher, mostly because it's similar to two parallel amps driving 4 ohms each. An output stage with gain and high current capability is what you'll end up with most likely IMO. Finding so many matched complimentary pairs can be frustrating and expensive 🙁
for the FE gain: I will try AlephP first since it is already there with an integrated attenuator; AP can swing it up to 20V (bal) only. if that does not do it, I will throw in the BA3 FE (a.k.a light F5) to get the extra few volts.
for the alephP PS: Salas reg finds it difficult to get up to 60V (apparently it is doable but modded down with resistors in place of active ccs etc.). I will consider alternatives though if AP stays in the system, like I think it should for the compatibility with the subs where another AP bal outputs drive Icepower modules in bridged mode, and two APs feature identical dantimax attenuators so they respond to the same remote control (I know it is a strange setup but shell I remind you: "the evolution" is to blame 🙂).
for the alephP PS: Salas reg finds it difficult to get up to 60V (apparently it is doable but modded down with resistors in place of active ccs etc.). I will consider alternatives though if AP stays in the system, like I think it should for the compatibility with the subs where another AP bal outputs drive Icepower modules in bridged mode, and two APs feature identical dantimax attenuators so they respond to the same remote control (I know it is a strange setup but shell I remind you: "the evolution" is to blame 🙂).
60V is easy task , if that sort of voltage was taken as goal from the start
in any case , it's hard, if not impossible, to make Wild West Elixir apparatus , covering all current and all voltage range , Greedy Boyz will ever want
many roads , if not all , are leading to Rome
just choose one , having shunt reg for 60V nearby
ok - Shunty - as bipolar one , would be waste
but - you can find some more adequate around , if you search
in any case , it's hard, if not impossible, to make Wild West Elixir apparatus , covering all current and all voltage range , Greedy Boyz will ever want
many roads , if not all , are leading to Rome
just choose one , having shunt reg for 60V nearby
ok - Shunty - as bipolar one , would be waste
but - you can find some more adequate around , if you search
on a second thought, gainwise, I am pretty sure alephP will not make it driving balanced F4 because when loaded with the attenuator the gain is significantly lower. I checked last night with the 2kOhm balanced load (2X1k SE) and the gain was only x5 lin or ~14dB? the internal gain pot was backed up just a bit from the max gain (which when unloaded measured 21.5dB).
so if the balF4 can make it into 4ohm load the FE will be the BA-3.
so if the balF4 can make it into 4ohm load the FE will be the BA-3.
In parallel, yes, but if you run F4 as bridge balanced monoblock, it's 100WPC into 8 ohm. Almost double that into 4. 🙂
You would need to make BA-3 Front-end balanced, which means you must double up on everything, as it's a normally SE gain stage.
I would suggest taking very good look at Zen Mod's Pumpkin" preamp - it can run Balanced or SE in, Balanced or SE out, and has enough gain and voltage swing to drive Balanced F4 (or BA-3 complimentary output stage -which is an F4 without the Jfet input buffer.)
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yup
it will drive F4
though ..... even bridged balanced bridged balanced bridged balanced , slightly modified
it will drive F4
though ..... even bridged balanced bridged balanced bridged balanced , slightly modified
If you run Bal/Bridged F4/BBA-3 OS into 4 ohms, you could get:
About 18Wrms maximum ClassA output
200Wrms maximum ClassAB output(doubtful)
But, If you run Paralell F4/BBA-3 OSs into 4 ohms, you could get:
About 50Wrms maximum, ClassA output
Based of coarse on typical power supply Voltages. YMMV
About 18Wrms maximum ClassA output
200Wrms maximum ClassAB output(doubtful)
But, If you run Paralell F4/BBA-3 OSs into 4 ohms, you could get:
About 50Wrms maximum, ClassA output
Based of coarse on typical power supply Voltages. YMMV
flg, well I know that; the point is to stay balanced if at all possible so the question boiles down to what you markt as "doubtful'. so my concern is whether the fets can survive the current draw of 4 ohms. I will be putting an undersized Xformer into the monoblock, 450VA, with a +-24Vdc reg PS as per Zen5 article where the 2mH inductors and 120,000uF of capacitance per rail help the xformer with transient loads. I am still counting on PS to sag if a continuous load stays high and protect fets that way? this is just guesstimating though. Papa thinks the amp has a shot at it, and I hope the speakers will not call for running at max volumes so .
p.s. yeah, a
would be nice. maybe ZM can trade me one for something some day, hint hint 
. in the meantime BA3 FE will have to do (already have the boards for it and the PS can be shared for an integrated amp).
.p.s. yeah, a
would be nice. maybe ZM can trade me one for something some day, hint hint . in the meantime BA3 FE will have to do (already have the boards for it and the PS can be shared for an integrated amp).
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The F4 Spec states; max V output +-20V, max I out 5A 😀
To be connected in a bridged configuration means 40V max output but still only 5A maximum current.
5A in 4 ohms is 50wrms, shy of 200w, in fact, no more than 1 channel of a standard stereo connected F4. The F.W. F4 only uses 1 250VA xfmr.
Driving 4ohms in bridged mode is like driving 2 2ohm loads with a stereo configuration.
To be connected in a bridged configuration means 40V max output but still only 5A maximum current.
5A in 4 ohms is 50wrms, shy of 200w, in fact, no more than 1 channel of a standard stereo connected F4. The F.W. F4 only uses 1 250VA xfmr.
Driving 4ohms in bridged mode is like driving 2 2ohm loads with a stereo configuration.
As a standard F5, with just two output transistors per channel, has no problem with 4 ohm speakers, it's a safe bet that a F4, with 6 devices per channel, will have no problem at all.
A stereo F4 comes from the factory with a 300VA transformer, so I don't think yours will be undersized... 😎
Nope. It's not going to sag.
But there is nothing wrong with a big PSU as you describe.
Papa thinks the amp has a shot at it, and I hope the speakers will not call for running at max volumes so
Papa really loves understatement. So when he says "I think it will have a shot at it" you should read, "no problem at all".
yeah, a
I think, but correct me if I'm wrong, he will happily trade you a pumpkin for Euros.
You'll love the BA-3 as preamp. It's an amazing circuit.
makes sense now. I believe I still stated my question the right way for Papa to get my problem? I should be Ok with 50Wrms for midbass/high speakers (say 90Hz and up).
love that!! It's all good news then 🙂, incl the PS size 🙂.
I have a pretty good idea about what goes there since I originally come from a place half an hour drive from ZM (this is why he knows he can comment on the size of my heatsinks without consequences 😀). but, come to think of it, ordering a pumpkin from him would be underutilizing zengenious. he's into so many interesting things outside my realm: a J2-like creature?, an M2, or even tOOObz? (I never heard any). so many forbiden choices behind the curtain
.
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