I am new to this forum, and to DIY, and electronics in general. My understanding of most of this stuff is elementary at best, and I'm probably going way over my head with this, but I really want to build a pair of F5 Turbo v3's in the relatively near future (pending wife acceptance and wallet acceptance, of course!). After talking with a few people I know, I think I'll be alright, but I'm still slightly confused. This potential project is still in the early planning phase, so I'm trying to get all of my ducks in a row. My problem right now is this:
I'm having trouble understanding how to build the PSU. Looking at the Universal PSU V3, there's a bill of materials, and schematic, but I still am not entirely sure how to determine what input snubber resistors, caps, and input snubber caps I need... or anything else for that matter. I guess I'm just trying to figure out where am I supposed to start?
I realize that this is a fairly broad topic, and forgive me for my ignorance, but it seems the only way to learn is to... do it yourself (excuse the pun). Any help would be greatly appreciated. Thanks a ton.
I'm having trouble understanding how to build the PSU. Looking at the Universal PSU V3, there's a bill of materials, and schematic, but I still am not entirely sure how to determine what input snubber resistors, caps, and input snubber caps I need... or anything else for that matter. I guess I'm just trying to figure out where am I supposed to start?
I realize that this is a fairly broad topic, and forgive me for my ignorance, but it seems the only way to learn is to... do it yourself (excuse the pun). Any help would be greatly appreciated. Thanks a ton.
At first i would look how to work safely with mains voltage. And safe work with electronics in general.
Not that you accidentally kill yourself.
For making a PSU you can read the article -power supplies- from PASSDIY.com
Not that you accidentally kill yourself.
For making a PSU you can read the article -power supplies- from PASSDIY.com
Don't use the snubbers, input nor output, on a Class-A amp.
Makes it quite a bit easier, yes? 🙂
That said, do you live somewhere cool, as a pair of F5Tv3 is literally room-heating... ?
Would this be your first project?
You say you don't know where to start - that's easy; chassis. Determine exactly what you are going to do for chassis and work from there. Look at the 5U deluxe from the diyAudio store, it's about the minimum size for one channel. Deluxe 5U "Big Amp Chassis" (All Aluminum) V2 - Full width with 40mm Heatsinks - Chassis
Check your PM.
Makes it quite a bit easier, yes? 🙂
That said, do you live somewhere cool, as a pair of F5Tv3 is literally room-heating... ?
Would this be your first project?
You say you don't know where to start - that's easy; chassis. Determine exactly what you are going to do for chassis and work from there. Look at the 5U deluxe from the diyAudio store, it's about the minimum size for one channel. Deluxe 5U "Big Amp Chassis" (All Aluminum) V2 - Full width with 40mm Heatsinks - Chassis
Check your PM.
Shersch:
Although I've built an array of projects, I still consider myself a newbie because I lack the knowledge and expertise that is commonly found at diyAudio. This is, truly, an amazing site and community. After about a year of planning and work, I completed a pair of F5T V3 amps earlier this year. I couldn't be happier with them (other than having a burning desire to play with P3). But as an electronics ignoramus, I gotta say that I would not make the F5T V3 my first foray into amplifiers. The project was hard enough as it was, and I've been playing at the edge of this sandbox for almost 10 years. Getting excited and challenging yourself with your first project is one thing. The F5T V3 is another.
I suggest you find a simpler project to get your feet wet before tackling the V3.
Regards,
Scott
Danger Mouse, thanks, I found an article on the passdiy site.
toxic, Pennsylvania, why?
6L6, i'm willing to make my electric bill go up if my gas bill goes down 😀
this is not my first time building amps, but i haven't done anything of this magnitude. i don't know if you guys are familiar with carver, but i built a few of the VTA20S tube amps for some of the carverfest guys that either didn't know how or didn't have time.
SRMcGee, this is definitely not my first time with a soldering iron; I have spent the last two years learning how to repair equipment (although nothing by Nelson Pass has ever come by me), and as I mentioned, I built a few tube amps. I am not afraid of the challenge, and I definitely have the resources, between the expertise on this website, and a couple of friends that I learn from. I am currently in the very early stages of planning anything, but the v3 is simply the only thing that had enough power to capture my interest. given, my speakers are going to be a nightmare to power, and I would actually need SIX v3 monoblocks to power them, but these are definitely amps I want to build and enjoy. I wish I've been in this sandbox for 10 years, but ten years ago I was 13 and had my mind on more adolescent things. I have every intention of learning as much as I can from this forum before I even attempt the build, because A) I think I can learn a lot, and B) I would rather do it once, correctly.
Thanks a lot for the information though, guys. It is much appreciated.
Steve
toxic, Pennsylvania, why?
6L6, i'm willing to make my electric bill go up if my gas bill goes down 😀
this is not my first time building amps, but i haven't done anything of this magnitude. i don't know if you guys are familiar with carver, but i built a few of the VTA20S tube amps for some of the carverfest guys that either didn't know how or didn't have time.
SRMcGee, this is definitely not my first time with a soldering iron; I have spent the last two years learning how to repair equipment (although nothing by Nelson Pass has ever come by me), and as I mentioned, I built a few tube amps. I am not afraid of the challenge, and I definitely have the resources, between the expertise on this website, and a couple of friends that I learn from. I am currently in the very early stages of planning anything, but the v3 is simply the only thing that had enough power to capture my interest. given, my speakers are going to be a nightmare to power, and I would actually need SIX v3 monoblocks to power them, but these are definitely amps I want to build and enjoy. I wish I've been in this sandbox for 10 years, but ten years ago I was 13 and had my mind on more adolescent things. I have every intention of learning as much as I can from this forum before I even attempt the build, because A) I think I can learn a lot, and B) I would rather do it once, correctly.
Thanks a lot for the information though, guys. It is much appreciated.
Steve
If you lived near-by, I was going to meet up with you and share notes, etc. I'm in Arizona, if you want to stop by. Getting chilly here. Down into the 60s at night and only about 93 today.
Ah, I appreciate the offer, but unfortunately a random trip to Arizona isn't in my budget haha.
If the PSU is ringing, then snubber/s is/are required to eliminate the ringing.
It does not matter whether a ClassA, or ClassAB, or ClassB, or ClassD, or ClassH amplifier is being fed.
same boat
I'll pipe in as I feel to be in a similar if not same boat as the thread originator having found my way to Pass diy through tube builds and a stint of repair work.
The v3 is kinda kinda scary.
Go for it but color inside the lines - just build what Nelson Pass put down.
I'm still watching what others are doing. There is an active thread for a fellow in HI. Problems incurred with stepping beyond seem difficult to overcome. I'm not there yet but maybe you are.:🙂
I'll pipe in as I feel to be in a similar if not same boat as the thread originator having found my way to Pass diy through tube builds and a stint of repair work.
The v3 is kinda kinda scary.
Go for it but color inside the lines - just build what Nelson Pass put down.
I'm still watching what others are doing. There is an active thread for a fellow in HI. Problems incurred with stepping beyond seem difficult to overcome. I'm not there yet but maybe you are.:🙂
Yeah, no question. I have no intention of doing anything more than Pass initially designed; at least not until the unit is completed and functioning. After some thinking, I'm actually leaning toward making the V1. Basically, my issue is that my speakers are tri-ampable only; can't make them stereo or biamp. In other words, whatever I make, I'm going to need three of it if I want to add it permanently to my setup. Maybe it's massive overkill, but 3 V1's has to sound absolutely stunning. I know that the most inefficient aspect of my speakers are the bottom end, and its driver is rated for 150w at 4 ohms, but it's not like I'd ever actually crank it that loud. I definitely have a lot of pondering to do before I start this. I think the topic of this thread is so far off from what I'm now curious about. Oh well, I suppose that's just a part of the process.
Shersch:
Where in Pennsylvania? I'm in Wynnewood, just outside the western edge of Philadelphia. If you're in the neighborhood and so inclined, I'm open to hosting a listening session.
Regards,
Scott
Where in Pennsylvania? I'm in Wynnewood, just outside the western edge of Philadelphia. If you're in the neighborhood and so inclined, I'm open to hosting a listening session.
Regards,
Scott
Scott, I'm in Pittsburgh. I would be very interested in hearing those V3's though... Maybe some time in the relatively near future I'll take my wife on a short trip to NYC, and we'll accidentally get lost on the way so I can take a listen haha. Thank you for the offer though.
Shersch:
No problem. Ping me if you ever visit the other side of the Commonwealth.
Regards,
Scott
No problem. Ping me if you ever visit the other side of the Commonwealth.
Regards,
Scott
That would be an input snubber...
But to answer your original question, a snubber is there to damp the ringing of the circuit when there is a large transient load. A class-A amp should have a constant draw, making no need for something to damp variations in current draw.
But to answer your original question, a snubber is there to damp the ringing of the circuit when there is a large transient load. A class-A amp should have a constant draw, making no need for something to damp variations in current draw.
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I thought a snubber on the transformer secondaries was to damp the ringing triggered by the operation of the rectifier.
Stop promoting the idea that ClassA is constant current.
You are wrong.
Only a few ClassA topologies have the constant current characteristic. These few topologies are very rarely adopted.
The vast majority of ClassA amplifiers are NOT constant current load on the power supply.
BUT,
your whole premise is based on the wrong science. It's not the load that is the sole transient impulse on the PSU.
It's the diodes in the power rectifiers that give the transient pulse. They pass current in the reverse direction just as the supply voltage starts to drop below the stored voltage on the smoothing capacitors, while the diode junction capacitance is reverse charged.
The diodes then suddenly stop passing reverse current and that is the pulse that the transformer L plus smoothing C see as the invite to start ringing.
This LC ringing has nothing to do with the Class of the load.
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