luvdunhill said:
well, I hoarded a bunch of Delta 06AK2 modules from a guy on Ebay (in fact, there is still someone selling them there). If you search, you'll see an equivalent Qualtek part number, but after looking at the prices, you'll see why I bought 10 or so on Ebay for $3 each
I have never used them in a power amplifier, but I have in preamp and headphone amplifier projects with excellent success.
I'd be interested to hear other's opinion of using these on the F4.
if anything materializes, I may be interested as well. I haven't decided what I'm going to do for heat sinks... I'd really like to get a pre-assembled case, and preferably a Hi-Fi 2000 Pesante Dissipante, as this would coordinate with all my other DIY creations.
I'm waiting back for the ratings on the heatsink on their 5U chassis:
http://www.hifi2000.it/default.asp?id=104&mnu=104
Problem with Hi-Fi 2000 is the fact they will only send via expensive air mail ... But in the end, I have several models and they are "quite easy on the eyes" and by far my favorite cases that are readily available to the DIY-er.
The Pesante Dissipante looks nice. Please keep me informed of the price info you get.
Regarding R-Theta:
I have exchanged email with Ruby Reddy at R-Theta. The price is too high for a small individual order due to the minimum $250 order plus $50 setup. She suggested I try one of their distributors and I have sent an email in to Utrech. I will keep both of you informed. I am checking out both the 65340 profile, as bought in the 2002 group buy and the 66427. The latter one has slightly larger fins and may allow me to use a heatsink less than 11" high. My original goal of 6" does seem too optimistic though. I have played with R-Tools on their site and learned that I need a much larger heatsink than the 6" I had originally hoped for. I could not model the 66427 profile as this is not available with the tool. I exchanged email with Clifford Weasner at R-Theta and he just happens to be in the process of updating all of the extrusions in R-Tools so this should be available by Monday.
Again I will keep you informed.
Jim
Variac said:
yes- I know that we can be (or- we are) naugthy sometimes ,but please- keep us equal ;
at least in posts of off topic mob you'll rarely find any sign of disrespect for other members; unseriousness always,but not disrespect and sleazyness ; these two last things are more than evident in first- shinobivan's and then jleaman's posts.
at least shinobivan showed way more than just stupidity....
and yes- besides jleaman , I'm solely responsible for that incident
feel free to ban only me (of entire silly off topic bunch) for as much days you want .
My suggestion is that you all forget about this "incident" as fast as you can
Lucky me. I was too busy with other things, so I couldnt take part. Lucky YOU guy's, that Pinkmouse didnt see all this
I am sure he would have brought you to order and kicked you to Texas All of you! Both parties are out of line here. The OT-mobgang, never goes personal! Thats first priority. Happens on rare occations, I know! But usually its for a serious reason. ( I can remember one case and it might even have a follow-up. Depends!) On the other hand, dont get too offensive against the "Gang" Ups!
If all members that posted some OT stuff in this thread were deleted, what would be left?? I dont even think that PD would have considered doing a board GB then! Agree?
Looking from the outside, you will all agree with me some time in the future. Calm down, have fun and a beer. Afterall its Papa's birthday
Steen
Edit Sorry, I didnt mean to post this right after Mr. Pass
Lucky me. I was too busy with other things, so I couldnt take part. Lucky YOU guy's, that Pinkmouse didnt see all this I am sure he would have brought you to order and kicked you to Texas All of you! Both parties are out of line here. The OT-mobgang, never goes personal! Thats first priority. Happens on rare occations, I know! But usually its for a serious reason. ( I can remember one case and it might even have a follow-up. Depends!) On the other hand, dont get too offensive against the "Gang" Ups!If all members that posted some OT stuff in this thread were deleted, what would be left?? I dont even think that PD would have considered doing a board GB then! Agree?
Looking from the outside, you will all agree with me some time in the future. Calm down, have fun and a beer. Afterall its Papa's birthday
Steen
Edit Sorry, I didnt mean to post this right after Mr. Pass
Banned
Joined 2002
steenoe said:My suggestion is that you all forget about this "incident" as fast as you can
If all members that posted some OT stuff in this thread were deleted, what would be left?? I dont even think that PD would have considered doing a board GB then! Agree?
Looking from the outside, you will all agree with me some time in the future. Calm down, have fun and a beer. Afterall its Papa's birthday
Steen
Edit Sorry, I didnt mean to post this right after Mr. Pass
ERR!!! i sent this to many mod's no one wanted to take responsibility and clean it up.
jarthel said:
anyone else?
I know that the service manual says pass labs preamp can drive the F4 directly. But I am not sure if that only includes the recent X-series preamps.
The speakers that I will be using will be in between 90 to 95 db/w efficiency.
Thank for the reply
what spks
what room
listening habits
?
Attachments
Nelson Pass said:Unbalanced, the 1.7 will swing almost 20V peak and twice
that balanced. This is just short of what will clip the F4 in
single-ended or bridged mode.
The X series will do about 28V peak unbalanced, and about
twice that balanced, which is more than enough to clip the F4.
in plain english, is that a "yes, you can safely use an aleph 1.7 with the F4"?
Banned
Joined 2002
jarthel said:
Safely?
I confess that I don't understand how this amp has caused so much consternation, just by having unity gain.
Let's back up a moment and look at some simple numbers. Nothing kinky. Nothing weird. Just some realistic numbers.
An average power amp has something around 26dB gain. Is there anything sacred about this figure? No. It's just a semi-conventional figure that the industry tends to use. It works out to amplifying the signal by 20x. The Aleph amps have somewhat less gain--20dB if I recall correctly. These days a preamplifier generally has something between 10dB and 20dB of gain. Just to keep things simple, let's assume you're using a CD player (which generally has a fairly hot output) and that your preamp has 14dB gain (5x). Now rouse a few brain cells and do the math: 26dB plus 14dB equals 40dB total available gain.
But--being possessed of super powers--I happen to know that you never use that much. You'd have to crank the volume knob all the way clockwise, something few people ever do. Actually, it's likely that you end up in the 10 to 12 o'clock position...and that's on loud days.
Now, here's your homework: Put a known signal into your preamp and set your volume knob so that the output equals the input. For example, if you put in one volt, then set the volume knob so that you're getting one volt out. Put a piece of masking tape next to the volume knob and make a little hash mark at that point. This is 0dB gain. Your volume knob is now calibrated. Kinda sorta. For extra credit and since you've already got the masking tape in hand, go ahead and mark a few more useful places, such as +3dB, -3dB, +10dB, -10dB...etc.
If your preamp is at -6dB gain at what you regard as a reasonable listening level and you use an Aleph amp (20dB gain), then you're using around 14dB overall gain in your system. This tells you that you'll need a preamp with that much gain and with enough voltage swing so that it doesn't clip when driving the F4 rail to rail. In reality, it wouldn't hurt to have a little extra.
Okay, time for a reality check. The Aleph 1.7 preamp specs show 22dB gain balanced/16dB unbalanced. That sounds pretty good. How about the voltage swing? A quick perusal of the specs shows 20Vrms balanced/10Vrms unbalanced.
Given that the stock F4 is quoted as swinging +-20V, and given that you know it has unity gain, you'd like to be able to swing +-20V (40V overall) from the preamp--that means peak voltage, not RMS.
A little quick math shows that the preamp can swing well over 50V from peak to peak.
Spend a little more time with your thinking cap on and you can answer these questions for yourself. Questions are always welcome here, but people like to see that you're actually putting some effort in, yourself, rather than spraying questions all over the place because you're not thinking things through.
Grey
jarthel,
As a follow-on, I see that you have started something like ten threads in the last twenty-four hours, each with a single question--mostly pretty elementary stuff that's been flogged to death in a hundred other threads.
Please think before you post. Search this site. Read a book or two. Look things up on the web. Spend a few minutes with a calculator. People lose patience when someone requests pre-digested answers every ten minutes. I haven't read all your threads, but I did catch one where another member has cautioned you against asking so many silly questions. Heed his warning.
Grey
P.S.: It doesn't help your cause any when people throw in suggestions that don't fit your narrow idea of what you want to hear (e.g. your cap thread). How will you learn if you shut out anything outside your current viewpoint?
As a follow-on, I see that you have started something like ten threads in the last twenty-four hours, each with a single question--mostly pretty elementary stuff that's been flogged to death in a hundred other threads.
Please think before you post. Search this site. Read a book or two. Look things up on the web. Spend a few minutes with a calculator. People lose patience when someone requests pre-digested answers every ten minutes. I haven't read all your threads, but I did catch one where another member has cautioned you against asking so many silly questions. Heed his warning.
Grey
P.S.: It doesn't help your cause any when people throw in suggestions that don't fit your narrow idea of what you want to hear (e.g. your cap thread). How will you learn if you shut out anything outside your current viewpoint?
jarthel said:I got no idea what you're talking about!
can give me a link to a tutorial?
http://www.bcae1.com/