Ok, thank you. Upon revisiting the diy store to follow the BOM in which to order parts for it, there was a note (IIRC) that said to change the voltage (IIRC) or power values for the components if need be. I didn't remember this from when I started getting all of this together.
I had it all in my head at one time, and as long as I stay fresh in it, I'm good, but I set this project aside for a spell and don't remember exactly where I was at with it all. Actually, it is the ACA's fault. I got hooked on listening to that instead and procrastinated everything else.
Time to build the V3's
Hello all, it's been one year since a finished my F5TV2, it made me sell the Bryston pre and amp I had at the time. I am using the salas DCG3 as my preamp.
Last year I purchase all the parts to build the monoblocks if I liked the sound and I do. So, it is time to covert the V2 to V3 and build the second amplifier.
I have learn some about power supplies and audio circuits but I am still ignorant about individual parts and their effect on the final sound.
It will take me a few days of work to put the amplifiers together, I would like to get the most of the time spent and get the best sound possible. My plan is to build the power supplies in separate enclosures to reduce noise and improve to quality of the parts used in the signal path.
The current F5TV2 i have was buit using the board kit and BOM suggested by the store.
How much benefit can one expect by using more exotic components in the signal path of front board and the output stages? Is it worth the effort and cost to procure these parts? these will be resistors and hook up wire.
Thank you in advance for your advice.
Hello all, it's been one year since a finished my F5TV2, it made me sell the Bryston pre and amp I had at the time. I am using the salas DCG3 as my preamp.
Last year I purchase all the parts to build the monoblocks if I liked the sound and I do. So, it is time to covert the V2 to V3 and build the second amplifier.
I have learn some about power supplies and audio circuits but I am still ignorant about individual parts and their effect on the final sound.
It will take me a few days of work to put the amplifiers together, I would like to get the most of the time spent and get the best sound possible. My plan is to build the power supplies in separate enclosures to reduce noise and improve to quality of the parts used in the signal path.
The current F5TV2 i have was buit using the board kit and BOM suggested by the store.
How much benefit can one expect by using more exotic components in the signal path of front board and the output stages? Is it worth the effort and cost to procure these parts? these will be resistors and hook up wire.
Thank you in advance for your advice.
I have built identical amps (preamps, actually)...one with dale rn series resistors and regular wire...and one with Takman metal films, silver soldier and fancy wire.
I couldn’t listen to them back to back (I used the same psu) but I didn’t feel there was any change.
That being said my f5 has PRP resistors and Teflon wire. I sleep better that way.
I couldn’t listen to them back to back (I used the same psu) but I didn’t feel there was any change.
That being said my f5 has PRP resistors and Teflon wire. I sleep better that way.
Active components (transistors, etc.) can make a big difference, but those are pretty much fixed in the F5 design. Passive components (resistors, caps, wire) not so much.
On the other hand, cognitive bias is very real. If you think they'll make a difference you may hear a difference (whether it's there or not), and that's really all that matters.
On the other hand, cognitive bias is very real. If you think they'll make a difference you may hear a difference (whether it's there or not), and that's really all that matters.
I like PRP in the horizontal resistors on the schematic (not the feed back as they need to be 3 watt or more). And the load resistor on the input. Forget silver solder.
Wire is what ever your preference is. I use Transparent "The Wall" 12 gauge for internal heavy wire and Transparent "SAP" interconnect for RCA to input board, because I have a ton of it laying around. (gutted a local AV store that closed.)
I sleep better and I swear I can tell a difference.
Now can't A/B this, so it could be in my head, but sleep is getting harder for me as I get older and if the knowledge that I used the best parts I could helps me sleep, then I'm going for it.
As far as how much difference? Well, probably not much.
Rush
Thank you for the input! I really like the amp, I kind of put it together somewhat in a hurry because I was anxious to hear it. It turned out very good, it has been solid for one year, now it's time to move slowly with the new build perhaps it will sound better, we'll see.. I like it the way it is now.
Thanks!
Thanks!
If you don’t need the increased wattage if v3 it’s possible that a high biased v2 would sound better. Just saying. Lower voltage rails let’s you bias higher.
For active devices you can try a different mosfet, Iam using toshibas. Hard to get and must be matched though. Or Fairchilds if you are using IRFa now. Subtle change but I believe the Toshibas sound best, I have tried all 3.
Also, there has been some discussion of source resistors having effects on sound. You could put your money there. Also, CLC instead of CRC.
If it was me I’d spend my money on chassis (more heatsink for higher bias) and caps/chokes for the psu. And leave it v2 unless you need the wattage.
For active devices you can try a different mosfet, Iam using toshibas. Hard to get and must be matched though. Or Fairchilds if you are using IRFa now. Subtle change but I believe the Toshibas sound best, I have tried all 3.
Also, there has been some discussion of source resistors having effects on sound. You could put your money there. Also, CLC instead of CRC.
If it was me I’d spend my money on chassis (more heatsink for higher bias) and caps/chokes for the psu. And leave it v2 unless you need the wattage.
Hard to believe you sq deteriorates at 70db. That’s very low. I listen at 85-90db with 50w v2 (32v rails) and 87db 3 ways (3.2ohm minimum). Amp is biased at 2 amps.
Increased bias will increase class a envelope into low ohms. But if you are running out of headroom that’s a different problem. I would think you should be able to get way above 70db without the amp struggling very easily.
Are you sure your speakers are ok?
Increased bias will increase class a envelope into low ohms. But if you are running out of headroom that’s a different problem. I would think you should be able to get way above 70db without the amp struggling very easily.
Are you sure your speakers are ok?
I'm surprised you haven't toasted your input JFETs with those rail voltages. You definitely want at least the cascoded input part of V3 for +/- 43V.
Does your preamp have enough gain to drive the F5T2 to max voltage? If so you should be delivering around 100W into 3 ohms, at which point you're current-starved. Increasing bias to 1 amp should get you to 160W. Above that you need the additional output devices of V3.
Does your preamp have enough gain to drive the F5T2 to max voltage? If so you should be delivering around 100W into 3 ohms, at which point you're current-starved. Increasing bias to 1 amp should get you to 160W. Above that you need the additional output devices of V3.
Speakers ok? I can try other set I have. Have not done it. SPL levels checked with a mobile phone app, not very precise.
I'm running the Jfets cascoded, i remember checking the voltage divider circuit, I think they are ok. But will check again.
I am glad I decided to post on the board, thank you! New ideas to explore.
I'm running the Jfets cascoded, i remember checking the voltage divider circuit, I think they are ok. But will check again.
I am glad I decided to post on the board, thank you! New ideas to explore.
I saw that 3 times with the output devices, shorted pins once, thermal run away adjusting bias twice, trim pots problems? Not sure but I replace them, I also changed the value of one resistor to make biasing more stable but I don't remeber which one, it is in my notes. Now, I am a lot more careful. Wife doen'st like the smell of the magic smoke