Yea..I feel foolish... I already removed all 8 caps.
Oh well. I wasn’t happy with my soldering job so I’ll make it nicer!
Thanks again for the help.
I’m planning on biasing both sides at .4V.
Im at .375V now and heatsinks are just warm in the 5u chassis.
Oh well. I wasn’t happy with my soldering job so I’ll make it nicer!
Thanks again for the help.
I’m planning on biasing both sides at .4V.
Im at .375V now and heatsinks are just warm in the 5u chassis.
Remember you need to bias below where the diodes kick in and take off... refer to the original article. This is the one amp where you just can't crank it till your heatsinks are maxed out.
Or just jenk out the diodes and turn the bias up a bit 🙂
BTW. I would still cascode the J-fets.
BTW. I would still cascode the J-fets.
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adjusting gain of f5turbo to match diy sony vfet
seeking help from experts, currently i have a foolish plan to utilise all my diy amp into 1 main system. running sony vfet diy for the tweeter / mid and a pair of f5turbo v2 monoblock for the bass. coupling with a dcb1 preamp. full diyaudio system 😀
after some readings i realise i need to match the gains of this 2 different amps. my vfet is fully done while f5turbo is at the final stages. can a few resistor change in the feedback reduce the gain to match the vfet in the front? if so may i have a rough ballpark value for the resistors?
from some readings:
vfet gain = 16db
f5turbo v2 = 22db
appreciate help in advance!
regards,
askae
seeking help from experts, currently i have a foolish plan to utilise all my diy amp into 1 main system. running sony vfet diy for the tweeter / mid and a pair of f5turbo v2 monoblock for the bass. coupling with a dcb1 preamp. full diyaudio system 😀
after some readings i realise i need to match the gains of this 2 different amps. my vfet is fully done while f5turbo is at the final stages. can a few resistor change in the feedback reduce the gain to match the vfet in the front? if so may i have a rough ballpark value for the resistors?
from some readings:
vfet gain = 16db
f5turbo v2 = 22db
appreciate help in advance!
regards,
askae
no need to match gains
you need to set input levels to get linear acoustical output from speaker drivers
you need to set input levels to get linear acoustical output from speaker drivers
thank you. i’ll ask questions in dcb1 thread instead to understand how i could fine tune the input level.
regards,
askae
regards,
askae
So I am starting off my DIY career with the F5T V2. Inherited project, so a bit scary and extremely motivating. But I have very good help, so I will succeed, hopefully. But I need you guys too!
It’ll be a dual mono build, details to come.
But first off: I notice a few possible misprints on the output boards, that have been corrected in at least one thread I have read.
Referring to the original schematic, R13-16 (gate resistors): are these the ones marked R1-4 on the stores output boards? I know the C2 is the equivalent of the schematics C3/4. But havent been able to find the explanation for R13-16.
6L6: Can you clarify? And if applicable, adjust your first post in this thread with both the correction wrt C2 and possibly R13-16? I might be wrong here, so I am prepared to stand corrected. And of course I know it is possible to look at the boards and understand this, but I need all the straight-forwardness I can get.
Ill be posting pictures in the builders thread as I go along. Need to pick up the half-finished build first, and will then be starting with the PSU, which is complex enough for starters.
Regards,
Andreas
It’ll be a dual mono build, details to come.
But first off: I notice a few possible misprints on the output boards, that have been corrected in at least one thread I have read.
Referring to the original schematic, R13-16 (gate resistors): are these the ones marked R1-4 on the stores output boards? I know the C2 is the equivalent of the schematics C3/4. But havent been able to find the explanation for R13-16.
6L6: Can you clarify? And if applicable, adjust your first post in this thread with both the correction wrt C2 and possibly R13-16? I might be wrong here, so I am prepared to stand corrected. And of course I know it is possible to look at the boards and understand this, but I need all the straight-forwardness I can get.
Ill be posting pictures in the builders thread as I go along. Need to pick up the half-finished build first, and will then be starting with the PSU, which is complex enough for starters.
Regards,
Andreas
I'm a beginner here. Looking to start a F5T v2 stereo build, and getting my shopping list together. The PSU has a BOM for parts, as does the amp, but none of them specifically mention the transformer. I heard I want a 32V transformer, and I suspect it should be a toroidal type, which narrows it down to 600 on digikey. What else am I looking for here? I'm in US, so 60Hz 110-120V AC at the wall. thanks!
https://i.imgur.com/cxO9a0Z.png
https://i.imgur.com/cxO9a0Z.png
Take a look for one here (decide for VA and go for needed V out): Transformers - Page 1 - AnTek Products Corp
You want +/-32VDC. Transformer sec 2x24VAC or 2x25VAC give you around +/-32VDC.
For a F5 turbo V2 stereoamp with 1 PSU you need minimum 600VA transformer.
A cascode F5T can easily handle 40V+ rails. A 32vac transformer would keep the voltage under 50VDC, which increases the choice of available filter capacitors.
@alexkosha @6l6 and @audiosan
thank you very much! I think this one fits the bill? $113 digikey Hammond 1182P117 625VA toroidal, primary 117V, secondary Parallel 117V, Series 234V, Parallel 5.34A, Series 2.67A.
Oh boy. I have a lot to learn, I may never get it! I made it about a third through the F5 User Manual, and my eyes had been crossed for the last five pages. I'm thinking I don't have an electrical sort of mind. My hope is that you folks help me get it right. Then through tinkering and effort, which I have in spades, some of the other stuff might start to click into place!
I'll post my full digikey BOM here in a big for posterity.
thank you very much! I think this one fits the bill? $113 digikey Hammond 1182P117 625VA toroidal, primary 117V, secondary Parallel 117V, Series 234V, Parallel 5.34A, Series 2.67A.
Oh boy. I have a lot to learn, I may never get it! I made it about a third through the F5 User Manual, and my eyes had been crossed for the last five pages. I'm thinking I don't have an electrical sort of mind. My hope is that you folks help me get it right. Then through tinkering and effort, which I have in spades, some of the other stuff might start to click into place!
I'll post my full digikey BOM here in a big for posterity.
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This one will do the job: AN-6225 - 600VA 25V Transformer - AnTek Products Corp
Or this one: AN-8225 - 800VA 25V Transformer - AnTek Products Corp
closing in on a completed plan and BOMs from mouser
I have a list of questions that might help someone else? We'll see.
I'm building a stereo F5Turbo V2.
1. am I building two Front End (FE) boards? I think yes.
If so, I need to double the number of resistors on the "BOM for DIYaudio F5 Turbo"
2. Am I building one or two Universal Power Supply (PS) boards? I think one board, which has what looks like two mirrored boards: 8 total large capacitors. $25 from diyaudiostore
3. 5Kohm bourns multi-turn potentiometer. Many to choose from. I chose these two based on pictures, and the schematic: three poles in a line. 4x 652-3266Y-1-502LF, and 2x 652-3266Y-1-201LF
4. finally, and probably most complicated: I need values for R25,26.27,R28. Calculating cascode voltage, and rail voltage. I don’t know where to start. I need a couple of known values to plug into the formula, to solve for something, that I’m not sure what to do with anyhow.
I’d like to end up with the 50 watts per channel that is described as the default here. Now, can I work backwards from there?
mouser BOM F5Turbo v2 stereo $80
mouser BOM Universal Powersupply $60
Antek 600VA 24V transformer $65 antekinc.com 2 outputs, 24V 12.5A
diyaudiostore $591 for:
1x F-5T pcb kit with six boards $49
1x universal power supply $25
1x quad linear systems matched jfets $39 (LSK170/LSJ74 ±0.1mA Matched Quad (Grade B))
1x F-5T v1/2 transistor kit $79
1x 5U chassis $399
Grand total ~$800 (probably plus some tax and shipping)
I have a list of questions that might help someone else? We'll see.
I'm building a stereo F5Turbo V2.
1. am I building two Front End (FE) boards? I think yes.
If so, I need to double the number of resistors on the "BOM for DIYaudio F5 Turbo"
2. Am I building one or two Universal Power Supply (PS) boards? I think one board, which has what looks like two mirrored boards: 8 total large capacitors. $25 from diyaudiostore
3. 5Kohm bourns multi-turn potentiometer. Many to choose from. I chose these two based on pictures, and the schematic: three poles in a line. 4x 652-3266Y-1-502LF, and 2x 652-3266Y-1-201LF
4. finally, and probably most complicated: I need values for R25,26.27,R28. Calculating cascode voltage, and rail voltage. I don’t know where to start. I need a couple of known values to plug into the formula, to solve for something, that I’m not sure what to do with anyhow.
I’d like to end up with the 50 watts per channel that is described as the default here. Now, can I work backwards from there?
mouser BOM F5Turbo v2 stereo $80
mouser BOM Universal Powersupply $60
Antek 600VA 24V transformer $65 antekinc.com 2 outputs, 24V 12.5A
diyaudiostore $591 for:
1x F-5T pcb kit with six boards $49
1x universal power supply $25
1x quad linear systems matched jfets $39 (LSK170/LSJ74 ±0.1mA Matched Quad (Grade B))
1x F-5T v1/2 transistor kit $79
1x 5U chassis $399
Grand total ~$800 (probably plus some tax and shipping)
Hello. it says F5 turbo V2. i expect +/-32 VDC. if so.
cascoding is easy. R25,R27 and R26,R28 = 4.75Kohm. that leaves obout 16VDC for the J.fets.
cascoding is easy. R25,R27 and R26,R28 = 4.75Kohm. that leaves obout 16VDC for the J.fets.
Hello all!
Looking at building a F5T v2 with standard 32v rails. A couple questions have come to mind..
I have a diyaudio ps board with 35v caps from an earlier F5 build. Would these be sufficient for the higher voltage in the turbo? Or should I plan on a new board using 50v caps? I'm not sure how much headroom is required here.
If I were to use an 800va transformer, what is the preferred soft start method? I remember seeing a comment somewhere that the CL60s are a good option up to 600va. Not sure where to go from there. The store is out of the soft start boards at the moment unfortunately.
Appreciate the advice!
Greg
Looking at building a F5T v2 with standard 32v rails. A couple questions have come to mind..
I have a diyaudio ps board with 35v caps from an earlier F5 build. Would these be sufficient for the higher voltage in the turbo? Or should I plan on a new board using 50v caps? I'm not sure how much headroom is required here.
If I were to use an 800va transformer, what is the preferred soft start method? I remember seeing a comment somewhere that the CL60s are a good option up to 600va. Not sure where to go from there. The store is out of the soft start boards at the moment unfortunately.
Appreciate the advice!
Greg