F6 Illustrated Build Guide
Mosfet F6 Illustrated Build Guide
The Firstwatt F6 is a power amplifier from the brilliant mind of our technical, spiritual, and menu advisor, Nelson Pass.
The F6 is unique in that it uses a transformer for phase inversion, and both phases (The ‘push’ and the ‘pull’) of the amplifier are powered by an N-channel device.
This guide uses this PCB set — F-6 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - Circuit Boards
Or here, the PCB with transformer bundled - F-6 Board + Transformer Kit – diyAudio Store
SCHEMATIC
The Schematic can be found here -
CHANGES TO THE SCHEMATIC - Change Z1, Z2 to a value higher than 5.1V if you need more bias. Increase in ~.5v steps until you can bias properly. The 1N4xxx series diodes are used here, 1N4733 is 5.1v, 1N4734 is 5.6v, 1N4735 is 6.3V, etc...
Suggested change, make R11, R12 110ohm. More information can be found in the BOM.
And an example PSU is here -
diyAudio PSU v3 build guide — diyAudio Power Supply Circuit Board v3 illustrated build guide
CHASSIS
The example amp is build into a diyAudio Deluxe 4U chassis — Deluxe 4U "Jack of all Chassis" (All Aluminum) V2 - Full width with 40mm Heatsinks - Chassis
Also utilized was the diyAudio Premium back panel parts kit — Error 404 - Page Missing
ASSEMBLY
Here are the PCB. The production boards are blue, and have some very slight changes to the silkscreen, but are otherwise identical.
Note that the PCB are a matched pair, not 2 of the same PCB. This is to facilitate keeping the input transformer as close to the back wall (and away from the power transformer) as possible.
Stuff resistors first.
After the resistors, stuff the larger components. Jfets, pots, capacitors, etc…
A stuffed PCB, sans transformer and LEDs (Didn’t have any blue ones on hand. 🙂 )
Input transformer. Note that on pair of pins is slightly narrower than the others. There are corresponding pads on the PCB for the narrow pins.
Transformer mounts here.
Both transformer mounted.
Remember, for best heatsink efficency, the mosfet should mount towards the bottom. This heatsink will make the left wall of the case.
You can see all the wiring of the PCB in this photo. (Red Black Green) is from the PSU, (Black White) is to the speaker posts, and the thin coax connects RCA to input.
Black is PSU GND and Speaker negative
White is Speaker positive
Red is V+
Green is V-
Input wiring from RCA
Completed, working amp. Need only to finish assembling the chassis around it.
(The black box on the transformer lead is a clamp-on ferrite clamp. Necessary? No. Might it help? Yes.)
POWER SUPPLY
IEC socket. You must wire the fuse holder to the switch as shown.
The long wires go to the terminal block with CL-60s, line cap and then the transformer primaries. I needed a bit huskier wire for the safety earth, and added the yellow for clarity.
PLEASE NOTE - this shows 120VAC wiring. Please consult your transformer for proper wiring for other voltages.
Into the block you can see the thermistors and cap, the AC mains from the IEC switch (Red Black) and the transformer primaries (Black Brown White Orange)
Safety earth and the CL-60 used to elevate PSU ground.
Two things to note - 1) I didn’t know if the power transformer was going to magnetically couple with the input transformers, so I wanted it as far away as possible. This will be almost touching the front plate. The L bracket was something I had from a salvage broken amp, so I can’t suggest a part number. Sorry. 2) Although I didn’t use the current PSU PCB, you can see that there is sufficient room (barely) for the board you can buy from the store.
I used an older diyAudio PCB that I had on hand, mainly because I really wanted to use it up.
Bridges mounted.
Wiring up the PCB.
More wiring.
For those of you wondering why I choose to have 2 big caps on one side and 4 on the other, it’s simply because I had those caps in my box. There’s no gain nor detriment to doing it in this manner.
The secret to clean wiring? Simple - start with your leads overly long and trim as you need to, and use lots of zipties. 😀
You can see the connections from transformer secondary to bridges and from bridges to PSU board.
PSU lit up.
TESTING AND POWERUP
Test PSU first for proper voltages BEFORE connecting amplifier circuit boards.
Then, connect only one amp PCB at a time.
Power Up
I suggest starting with a meter across the 0.47ohm source resistor, and watching it as it turns on, you want to have less than .5V across it to begin, turn it down with P2. If you start with the pot in it’s default position, it will most likely have too much bias initially. Turn off the power, turn down P2, and try again.
BIAS
P2 is marked BIAS on both PCB. Adjust this pot as necessary to set bias. Please note that as the pots and source resistors have the 1000uF capacitor in-between, the adjustments will happen in slow-motion and take a while to stabilize. Make small adjustments and wait as necessary. Patience is a virtue.
With DC voltmeter across the 0.47 source resistor, start by setting a bias reading of .5V (500mV) This will give a current of 1.05A, (.5V / 0.47ohm = 1.05A) which with a 24V rail gives about 25W of heat. Then zero your DC offset. Once you are satisfied that everything is stable and happy, you may increase the bias if you choose.
Remember the 3 rules of maximum bias… stop when you reach any of these -
Heatsink of 55C and/or Transistor pin 2 65C
Total bias , both channels, (in watts) of no more than 1/2 the power transformer’s VA
1/2 the maximum dissipation (in watts) of the output device. In the case of the IRFP240, it’s a 150W device, so no more than 75W. (Which is really, really hot…)
Generally, you will reach the 65C limit of the transistor before anything else.
OFFSET
P1is marked OFFSET on both PCB. Adjust as necessary to set 0V DC across the speaker terminals. Again, because the capacitor needs to charge and discharge as you make changes to the pot, any input to the pot will take some time to display on the meter, and it will seem as if it’s reacting in slow motion. This is normal.
Lightbulb Mains lead notes -
Please note that it must be an incandescent light bulb, not an LED or Florescent.
If the bulb ever turns on and stays bright, you probably have a short.
Normal operation when turning on a cold amp will have the bulb glow bright for a second or two, then dim, perhaps off. (this is the capacitors charging, then full)
As you increase the bias of the amp the bulb will glow brighter, and this is linear with the bias amount. A fully biased amp can get the bulb to glow very bright.
You cannot set full bias with the bulb in place - as it increases the bulb will glow more, limiting the voltage to the amp and all the readings will be wrong compared to when the bulb lead is out.
You can, however, set the initial bias with the bulb in place. Start the procedure, turn the pots until something happens, and set, at maximum, 0.1V across the source resistors and zero offset. Getting the pots started this way is a good idea. Remember, this is with a reduced voltage, and the pots will make the circuit draw MUCH more bias when the normal mains lead in used. Expect to measure 0.2V or more with a normal cord.
The Firstwatt F6 is a power amplifier from the brilliant mind of our technical, spiritual, and menu advisor, Nelson Pass.
The F6 is unique in that it uses a transformer for phase inversion, and both phases (The ‘push’ and the ‘pull’) of the amplifier are powered by an N-channel device.
This guide uses this PCB set — F-6 clone boards (2 PCBs, makes 2 channels; Rev 2.0) - Circuit Boards
Or here, the PCB with transformer bundled - F-6 Board + Transformer Kit – diyAudio Store
SCHEMATIC
The Schematic can be found here -
CHANGES TO THE SCHEMATIC - Change Z1, Z2 to a value higher than 5.1V if you need more bias. Increase in ~.5v steps until you can bias properly. The 1N4xxx series diodes are used here, 1N4733 is 5.1v, 1N4734 is 5.6v, 1N4735 is 6.3V, etc...
Suggested change, make R11, R12 110ohm. More information can be found in the BOM.
And an example PSU is here -
diyAudio PSU v3 build guide — diyAudio Power Supply Circuit Board v3 illustrated build guide
CHASSIS
The example amp is build into a diyAudio Deluxe 4U chassis — Deluxe 4U "Jack of all Chassis" (All Aluminum) V2 - Full width with 40mm Heatsinks - Chassis
Also utilized was the diyAudio Premium back panel parts kit — Error 404 - Page Missing
ASSEMBLY
Here are the PCB. The production boards are blue, and have some very slight changes to the silkscreen, but are otherwise identical.
Note that the PCB are a matched pair, not 2 of the same PCB. This is to facilitate keeping the input transformer as close to the back wall (and away from the power transformer) as possible.
Stuff resistors first.
After the resistors, stuff the larger components. Jfets, pots, capacitors, etc…
A stuffed PCB, sans transformer and LEDs (Didn’t have any blue ones on hand. 🙂 )
Input transformer. Note that on pair of pins is slightly narrower than the others. There are corresponding pads on the PCB for the narrow pins.
Transformer mounts here.
Both transformer mounted.
Remember, for best heatsink efficency, the mosfet should mount towards the bottom. This heatsink will make the left wall of the case.
You can see all the wiring of the PCB in this photo. (Red Black Green) is from the PSU, (Black White) is to the speaker posts, and the thin coax connects RCA to input.
Black is PSU GND and Speaker negative
White is Speaker positive
Red is V+
Green is V-
Input wiring from RCA
Completed, working amp. Need only to finish assembling the chassis around it.
(The black box on the transformer lead is a clamp-on ferrite clamp. Necessary? No. Might it help? Yes.)
POWER SUPPLY
IEC socket. You must wire the fuse holder to the switch as shown.
The long wires go to the terminal block with CL-60s, line cap and then the transformer primaries. I needed a bit huskier wire for the safety earth, and added the yellow for clarity.
PLEASE NOTE - this shows 120VAC wiring. Please consult your transformer for proper wiring for other voltages.
Into the block you can see the thermistors and cap, the AC mains from the IEC switch (Red Black) and the transformer primaries (Black Brown White Orange)
Safety earth and the CL-60 used to elevate PSU ground.
Two things to note - 1) I didn’t know if the power transformer was going to magnetically couple with the input transformers, so I wanted it as far away as possible. This will be almost touching the front plate. The L bracket was something I had from a salvage broken amp, so I can’t suggest a part number. Sorry. 2) Although I didn’t use the current PSU PCB, you can see that there is sufficient room (barely) for the board you can buy from the store.
I used an older diyAudio PCB that I had on hand, mainly because I really wanted to use it up.
Bridges mounted.
Wiring up the PCB.
More wiring.
For those of you wondering why I choose to have 2 big caps on one side and 4 on the other, it’s simply because I had those caps in my box. There’s no gain nor detriment to doing it in this manner.
The secret to clean wiring? Simple - start with your leads overly long and trim as you need to, and use lots of zipties. 😀
You can see the connections from transformer secondary to bridges and from bridges to PSU board.
PSU lit up.
TESTING AND POWERUP
Test PSU first for proper voltages BEFORE connecting amplifier circuit boards.
Then, connect only one amp PCB at a time.
Power Up
I suggest starting with a meter across the 0.47ohm source resistor, and watching it as it turns on, you want to have less than .5V across it to begin, turn it down with P2. If you start with the pot in it’s default position, it will most likely have too much bias initially. Turn off the power, turn down P2, and try again.
BIAS
P2 is marked BIAS on both PCB. Adjust this pot as necessary to set bias. Please note that as the pots and source resistors have the 1000uF capacitor in-between, the adjustments will happen in slow-motion and take a while to stabilize. Make small adjustments and wait as necessary. Patience is a virtue.
With DC voltmeter across the 0.47 source resistor, start by setting a bias reading of .5V (500mV) This will give a current of 1.05A, (.5V / 0.47ohm = 1.05A) which with a 24V rail gives about 25W of heat. Then zero your DC offset. Once you are satisfied that everything is stable and happy, you may increase the bias if you choose.
Remember the 3 rules of maximum bias… stop when you reach any of these -
Heatsink of 55C and/or Transistor pin 2 65C
Total bias , both channels, (in watts) of no more than 1/2 the power transformer’s VA
1/2 the maximum dissipation (in watts) of the output device. In the case of the IRFP240, it’s a 150W device, so no more than 75W. (Which is really, really hot…)
Generally, you will reach the 65C limit of the transistor before anything else.
OFFSET
P1is marked OFFSET on both PCB. Adjust as necessary to set 0V DC across the speaker terminals. Again, because the capacitor needs to charge and discharge as you make changes to the pot, any input to the pot will take some time to display on the meter, and it will seem as if it’s reacting in slow motion. This is normal.
Lightbulb Mains lead notes -
Please note that it must be an incandescent light bulb, not an LED or Florescent.
If the bulb ever turns on and stays bright, you probably have a short.
Normal operation when turning on a cold amp will have the bulb glow bright for a second or two, then dim, perhaps off. (this is the capacitors charging, then full)
As you increase the bias of the amp the bulb will glow brighter, and this is linear with the bias amount. A fully biased amp can get the bulb to glow very bright.
You cannot set full bias with the bulb in place - as it increases the bulb will glow more, limiting the voltage to the amp and all the readings will be wrong compared to when the bulb lead is out.
You can, however, set the initial bias with the bulb in place. Start the procedure, turn the pots until something happens, and set, at maximum, 0.1V across the source resistors and zero offset. Getting the pots started this way is a good idea. Remember, this is with a reduced voltage, and the pots will make the circuit draw MUCH more bias when the normal mains lead in used. Expect to measure 0.2V or more with a normal cord.
Hello DIYers!
- By NSky
- Introductions
- 1 Replies
Hello Everyone from Florida!
My name is Eugene, I enjoy building musical gear (like the 18W Marshal guitar amp clone below). Hope to find some new ideas here as well as some help with repairs.
My name is Eugene, I enjoy building musical gear (like the 18W Marshal guitar amp clone below). Hope to find some new ideas here as well as some help with repairs.
Class-D: Galvanically isolate the output stage?
Today many run their DACs directly connected to their class-d amps. I do. Amps with several 100 watts output and over 10A amps out.
I would guess that the signal ground in these amps are not the cleanest one could see. And here comes my culprit... the delicate ground in DACs where both clock ground and Vref grounds are tied up to the dirty class-d ground. Probably not ideal.
Why not make the PWM signal interface (red marking) after the "C" optical and let the input part float compared to the output stage. The only harmful part left sharing ground would be the triangle generator.
I bet such a combo of DAC and amp would be quite better sounding... what do You think?
//
I would guess that the signal ground in these amps are not the cleanest one could see. And here comes my culprit... the delicate ground in DACs where both clock ground and Vref grounds are tied up to the dirty class-d ground. Probably not ideal.
Why not make the PWM signal interface (red marking) after the "C" optical and let the input part float compared to the output stage. The only harmful part left sharing ground would be the triangle generator.
I bet such a combo of DAC and amp would be quite better sounding... what do You think?
//
For Sale SEAS MR18REX/XF (H1699) Coaxial Units with crossovers, Offers only please
- By Jeffrey 01
- Swap Meet
- 3 Replies
Attachments
MarkBass Little Mark 250 Bass Combo Amplifier - Need Help With Repair
- By NSky
- Instruments and Amps
- 3 Replies
Hello!
I got a faulty bass combo amplifier MarkBass Little Mark 250. But it appears to be a little more complicated than those I worked with before.
In general, I'm at a dead end, hoping for help from experienced forum members.
Symptoms:
The midpoint between the output darlingtons floats at idle relative to the ground (in the negative direction), when the difference reaches about 1V, the DC protection circuit is triggered and turns off the speaker.
While the amplifier is cold, it floats a lot. As it heats up, it stabilizes (it heats up decently, up to 60-70C degrees at idle) and works normally for a long time. Only sometimes the relay clicks for a second.
All supply voltages are normal, I unsoldered all the electrolytics, ESR is normal, does not show leaks...
Where to dig next?
How is this middle point adjusted there?
The purpose of some parts is a complete mystery to me, such as T3, T4, T6 for example...
I've drawn the schematic of the amplifier part of the combo:
I got a faulty bass combo amplifier MarkBass Little Mark 250. But it appears to be a little more complicated than those I worked with before.
In general, I'm at a dead end, hoping for help from experienced forum members.
Symptoms:
The midpoint between the output darlingtons floats at idle relative to the ground (in the negative direction), when the difference reaches about 1V, the DC protection circuit is triggered and turns off the speaker.
While the amplifier is cold, it floats a lot. As it heats up, it stabilizes (it heats up decently, up to 60-70C degrees at idle) and works normally for a long time. Only sometimes the relay clicks for a second.
All supply voltages are normal, I unsoldered all the electrolytics, ESR is normal, does not show leaks...
Where to dig next?
How is this middle point adjusted there?
The purpose of some parts is a complete mystery to me, such as T3, T4, T6 for example...
I've drawn the schematic of the amplifier part of the combo:
Rate my filtering
- By wafflesomd
- Multi-Way
- 55 Replies
Thought I'd see what people think about a little two way I've made before spending money on crossover components. Nothing too special, a Dayton DSA 135 woofer and SB26 STCN tweeter. I assumed there would be a dispersion mismatch and there is. There is also a notch in the DI at 350hz that I'm unsure of it's cause. Speaker was measured outdoors on a 10ft ladder. I have plenty of experience with active filtering but wanted to try passive for various reasons, one being to verify my measurement process.
Reverse null
Reverse null
Mark Levinson No. 36 DAC,,,NEED HELP
- By jc9394
- Digital Line Level
- 7 Replies
i have the Mark Levinson No. 36 D/A Converter, but it not working,
"NO CODE" is displayed upon power-up. how to repair it? thanks!
"NO CODE" is displayed upon power-up. how to repair it? thanks!
For Sale Binding post terminal cups - 60 available - great deal
New/unused - High quality compact terminal cups with gold-plated binding posts, 8awg bare wire/spade/banana/dual banana
$3 each - 60 available
$80 for all 60 pcs.
same as: https://www.parts-express.com/Round-Speaker-Terminal-2-15-16-Gold-Binding-Post-260-283
Please see photos below. Shipping from PA 18951 - not incl. /$TBD, either USPS or Fedex. PayPal only.
$3 each - 60 available
$80 for all 60 pcs.
same as: https://www.parts-express.com/Round-Speaker-Terminal-2-15-16-Gold-Binding-Post-260-283
Please see photos below. Shipping from PA 18951 - not incl. /$TBD, either USPS or Fedex. PayPal only.
For Sale CAPS! Film, F&F - Duelund, Mundorf, ClarityCap - priced to move
Please see photos below. Shipping from PA 18951 - not incl. /$TBD, either USPS or Fedex. PayPal only.
(Qty)
(2) Mundorf Supreme Silver/Oil 0.82uF 800VAC 1200VDC - $15 each (used, short leads)
(2) Duelund VSF stacked Cu foil 2.2uF no voltage rating - $25 each (used, full length leads) SOLD
(2) Russian Teflon FT-3 0.22uF 600V - $12 each SOLD
(2) ClarityCap MR 3.3uF 630V - $18 each (NOS/new) SOLD
(4) ClarityCap ESA 4.7uF 630V - $6 each, $20 for all 4 (NOS/new) SOLD
(3) ClarityCap ESA 1uF 630V - $5 each, $12 for all 3 (NOS/new)
(2) ClarityCap ESA 0.1uF/100nF 630V - $4 each (NOS/new)
(4 left) ClarityCap SA 3.9uF 630V - $4 each, $12 for all 4 (NOS/new)
(2/2/2/2/2) ClarityCap DTAC 630V M8 screw mount 2uF/2.7uF/3.3uF/4uF/4.7uF - $10 each or $60 for all 10 (used)
Thanks for looking! Make an offer for all if you like...
(Qty)
(2) Mundorf Supreme Silver/Oil 0.82uF 800VAC 1200VDC - $15 each (used, short leads)
(3) ClarityCap ESA 1uF 630V - $5 each, $12 for all 3 (NOS/new)
(2) ClarityCap ESA 0.1uF/100nF 630V - $4 each (NOS/new)
(4 left) ClarityCap SA 3.9uF 630V - $4 each, $12 for all 4 (NOS/new)
(2/2/2/2/2) ClarityCap DTAC 630V M8 screw mount 2uF/2.7uF/3.3uF/4uF/4.7uF - $10 each or $60 for all 10 (used)
Thanks for looking! Make an offer for all if you like...
Attachments
Board 3 Way DSP Amp
I will post the availability and price of the 3 Way DSP Amp boards here.
Read more about the boards here.
https://www.diyaudio.com/community/threads/3-way-dsp-amp.415065/#post-7734899
The price of one 3 Way DSP Amp board is $95.
The price of one I/O board is $15.
Delivery to Europe and America is at my expense. Delivery to islands or other distant places is negotiated separately.
Order more than one 3 Way DSP Amp board and get $5 off.
Payment via Payoneer.
We currently have four 3 Way DSP Amp boards and four I/O boards with ESP32 available.
Read more about the boards here.
https://www.diyaudio.com/community/threads/3-way-dsp-amp.415065/#post-7734899
The price of one 3 Way DSP Amp board is $95.
The price of one I/O board is $15.
Delivery to Europe and America is at my expense. Delivery to islands or other distant places is negotiated separately.
Order more than one 3 Way DSP Amp board and get $5 off.
Payment via Payoneer.
We currently have four 3 Way DSP Amp boards and four I/O boards with ESP32 available.
Lii Audio (not Lii Song) from Full-Range to Coaxial drivers! New models
- By Chakster45
- Full Range
- 17 Replies
Attachments
A60(+) Amplifier. Build this?
- By Berlusconi
- Solid State
- 958 Replies
Hello everyone.🙂
This is the first thread I have opened here with the aim to share my experiences with you and to broaden my knowledge about electronics from possible replies.
Over the 2020/2021 winter I have built an amplifier based on A60+ boards from eBay and was quite satisfied with the result: an amplifier sounds great, is relatively easy to build and involves everything what is needed to complete the project: power supply and effective speaker protection.
Below is a photo of one channel of the amplifier.
The amplifier comes in two different versions:
A60, smaller, with 3 output pairs of transistors
A60+, larger, with 8 pairs of output transistors.
There are variety of possible versions: with different output transistors
MJL3281A/MJL1302A
2SA1943/2SC5200
It is also possible to purchase bare boards, partially stuffed boards, complete boards and also amplifiers in chassis.
In addition to this the board incorporates a solid power supply and effective speaker protection. You only have to add your heat sinks large enough, transformers, transistors and capacitors.
I have decided initially for a A60+ version without output transistors and without power supply capacitors.
I also have tested A60+ and it sounds splendid indeed. Someone else on internet said its sound is "golden" and has gone that far to state that it has "euphoric tone". He is right it really sounds extraordinary. Just read this review.
I have also done extensive measurements: it measures great. It is done right across the whole audio spectrum and beyond. I will repeat the measurements and make them soon public.
The sound was great so I have decided to spend a bit more of time and money on this project.
I have purchased two A60+ and three smaller A60. This will be my spring 2021 project.
Finally, some hints for these who decide to build this amplifier:
Only capacitors with diameter 35mm and 10mm lead spacing will fit into this board. Initially I was afraid that just 4X10.000uF per channel wouldn't be enough, but it works indeed very well.
Carefully with biasing – this is a wild beast and can quickly go incredibly hot.
Chose heat sinks large enough to have freedom to set higher bias.
This is the first thread I have opened here with the aim to share my experiences with you and to broaden my knowledge about electronics from possible replies.
Over the 2020/2021 winter I have built an amplifier based on A60+ boards from eBay and was quite satisfied with the result: an amplifier sounds great, is relatively easy to build and involves everything what is needed to complete the project: power supply and effective speaker protection.
Below is a photo of one channel of the amplifier.
The amplifier comes in two different versions:
A60, smaller, with 3 output pairs of transistors
A60+, larger, with 8 pairs of output transistors.
There are variety of possible versions: with different output transistors
MJL3281A/MJL1302A
2SA1943/2SC5200
It is also possible to purchase bare boards, partially stuffed boards, complete boards and also amplifiers in chassis.
In addition to this the board incorporates a solid power supply and effective speaker protection. You only have to add your heat sinks large enough, transformers, transistors and capacitors.
I have decided initially for a A60+ version without output transistors and without power supply capacitors.
I also have tested A60+ and it sounds splendid indeed. Someone else on internet said its sound is "golden" and has gone that far to state that it has "euphoric tone". He is right it really sounds extraordinary. Just read this review.
I have also done extensive measurements: it measures great. It is done right across the whole audio spectrum and beyond. I will repeat the measurements and make them soon public.
The sound was great so I have decided to spend a bit more of time and money on this project.
I have purchased two A60+ and three smaller A60. This will be my spring 2021 project.
Finally, some hints for these who decide to build this amplifier:
Only capacitors with diameter 35mm and 10mm lead spacing will fit into this board. Initially I was afraid that just 4X10.000uF per channel wouldn't be enough, but it works indeed very well.
Carefully with biasing – this is a wild beast and can quickly go incredibly hot.
Chose heat sinks large enough to have freedom to set higher bias.
"Alte Schule" - The five-minute amplifier approach!
- By hbtaudio
- Solid State
- 64 Replies
Old school at the limit, inspired by the CD thread, a standard amp of the last millennium flowed from my fingers ... a kind of Santa Claus surprise today!
36 Peak Watts at 8 Ohm
Current Dumper without dump, only NFB.
TIP3055, BD139, BD140, BC5xx ... thats all we need.
Happy DIY,
HBt.
36 Peak Watts at 8 Ohm
Current Dumper without dump, only NFB.
TIP3055, BD139, BD140, BC5xx ... thats all we need.
Happy DIY,
HBt.
Lateral MOSFETs for sale, Exicon ECX10N20, ECX10P20, ECW20N20, ECW20P20
Hi all,
New and unused selected/matched (see attachment) Lateral MOSFETs bought from Profusion:
Single die, 200 V, 8 A, 125 W:
4 x ECX10N20 (Green dot)
4 x ECX10P20 (Red dot)
Double die, 200 V, 16 A, 250 W:
1 x ECW20N20 (Yellow dot)
1 x ECW20P20 (Yellow dot)
Sale price is 85 euros + shipping.
Regards,
VS
New and unused selected/matched (see attachment) Lateral MOSFETs bought from Profusion:
Single die, 200 V, 8 A, 125 W:
4 x ECX10N20 (Green dot)
4 x ECX10P20 (Red dot)
Double die, 200 V, 16 A, 250 W:
1 x ECW20N20 (Yellow dot)
1 x ECW20P20 (Yellow dot)
Sale price is 85 euros + shipping.
Regards,
VS
THD 0.00045% and 15 Watt
- By lineup
- Solid State
- 60 Replies
This is a simple all Symmetric Class AB amplifier.
Distortion is low: THD 0.00045% at 1 Watt into 8 Ohm.
The VAS is a differential stage to increase the gain.
Output is simply EXICON lateral MOSFET.
Max like 15 Watt at +/-20 Volt supply.
Can of course use higher supply with higher output power.
Distortion is low: THD 0.00045% at 1 Watt into 8 Ohm.
The VAS is a differential stage to increase the gain.
Output is simply EXICON lateral MOSFET.
Max like 15 Watt at +/-20 Volt supply.
Can of course use higher supply with higher output power.
Antek Transformer AS-05T320, 50VA 320V-300V-0V & 6.3V 2A x2 AS-05T320
- By kwong08823
- Swap Meet
- 0 Replies
Attachments
TIS/VAS, Driver transistores KSA1381E + KSC3503E + KSC3503D for sale
Hi All,
I have a stock of new transistores for sale:
130 -> 110 -> 55 x KSA1381E (Fairchild/On Semi)
130 -> 118 x KSC3503D (Fairchild/On Semi)
100 -> 80 -> 24 x KSC3503E (Fairchild/On Semi)
300 V / 0.1 A / 7 W / TO-126 / (grades D and E, hFE = 60-120 and 100-200).
Offers accepted for the whole lot.
Price per pair with a minimum qty of 20 pieces: 1.5 Euros/pair + Shipping.
For matching please PM.
Regards,
VS
I have a stock of new transistores for sale:
130 -> 110 -> 55 x KSA1381E (Fairchild/On Semi)
130 -> 118 x KSC3503D (Fairchild/On Semi)
100 -> 80 -> 24 x KSC3503E (Fairchild/On Semi)
300 V / 0.1 A / 7 W / TO-126 / (grades D and E, hFE = 60-120 and 100-200).
Offers accepted for the whole lot.
Price per pair with a minimum qty of 20 pieces: 1.5 Euros/pair + Shipping.
For matching please PM.
Regards,
VS
Attachments
"The Bog Standard" - A good enough amplifier for the rest of us
- By njswede
- Solid State
- 316 Replies
Well... Here goes nothing!
I've been reluctant to do this out of fear of ridicule. You see, I'm not a very experienced designer and the design I'm about to present is a pretty mundane Class AB job.
But lately I've seen beginners on various forums struggle with designs that require exotic and/or obsolete components or designs that require very stable power supplies and careful thermal management. I've also seen people having a tough time with what's clearly outdated or outright bad designs that are floating around. So based on that, I thought a fellow beginner might find this thread useful.
I decided to share a decent amplifier that can be built using cheap components that are readily available from almost any source. It uses only 2N5551/5401, BD139 and IRFP(9)240 transistors, some 1N4148 diodes, a couple of 5V zeners and a smattering of capacitors and resistors. That's it! It runs fairly cool, does fantastic with a modest 40mA bias current and has a net negative temperature coefficient with regard to bias if you're careful with the thermal transfer between the VBE multiplier and the output MOSFETs. It physical tests, it's fairly flat past 100kHz at 50% power and gets a decent 0.003% THD at 80% power and 1kHz in simulations. I don't have the equipment to measure an accurate physical THD, but just eyeballing it on the scope, it's definitely <0.1% and probably a lot less. Nothing compared to the Class A masterpieces some people here are building, but enough to sound pretty nice. The way it's drawn it should be good up to 50W with the right heatsink.
It's also very forgiving in terms of component values and (probably) layout. I've messed around in SPICE, and it takes real work to make it misbehave. You can even mess up the matching of the LTP transistors quite badly without it throwing a fit. It also has a >70 degree phase margin in simulations and would probably do fine with a lower Miller capacitance if someone wants faster performance. I've tried it with 8ohm and 6ohm speakers, and based on simulations it should have no problem at all with 4ohm as long as you're staying within a reasonable power (50W). The gain is 23x (27dB), which is a bit low for regular line level. You could probably bump it up a bit, but I'd probably recommend a pre-amp instead. I haven't checked the stability with a higher gain.
This design has been built and sounds and measures well. Audiophile quality? Probably not, but good enough to "open up" music I've listened to many times before and letting me discover new details.
I'll share the schematic and also a Github repo with all the design and simulation files, along with some ideas on how to build and test it. If you're a beginner, feel free to try it or just borrow ideas and inspiration. And if you're an experienced designer, I'm happy to listen to ideas for improvement. You can even clone the repo and send me a pull request if you want to contribute. But please be gentle! 🙂
There are a few things I'd like to change when I get a chance. The pot on the long tail can be replaced with fixed resistors and the terminal block for the speakers on the middle of the board is awkward. But it's buildable and works well in its current form. You could (and probably should) add speaker protection and maybe a preamp and some tone controls.
The repo: https://github.com/prydin/classab-amp-mosfet
I hope you'll find my humble contribution valuable in some way. And be gentle on me!
[EDIT: Updated the schematic with a protection diode for the VAS to avoid disasters... Also removed the DC offset pot, since it doesn't do much due to the current mirror]
I've been reluctant to do this out of fear of ridicule. You see, I'm not a very experienced designer and the design I'm about to present is a pretty mundane Class AB job.
But lately I've seen beginners on various forums struggle with designs that require exotic and/or obsolete components or designs that require very stable power supplies and careful thermal management. I've also seen people having a tough time with what's clearly outdated or outright bad designs that are floating around. So based on that, I thought a fellow beginner might find this thread useful.
I decided to share a decent amplifier that can be built using cheap components that are readily available from almost any source. It uses only 2N5551/5401, BD139 and IRFP(9)240 transistors, some 1N4148 diodes, a couple of 5V zeners and a smattering of capacitors and resistors. That's it! It runs fairly cool, does fantastic with a modest 40mA bias current and has a net negative temperature coefficient with regard to bias if you're careful with the thermal transfer between the VBE multiplier and the output MOSFETs. It physical tests, it's fairly flat past 100kHz at 50% power and gets a decent 0.003% THD at 80% power and 1kHz in simulations. I don't have the equipment to measure an accurate physical THD, but just eyeballing it on the scope, it's definitely <0.1% and probably a lot less. Nothing compared to the Class A masterpieces some people here are building, but enough to sound pretty nice. The way it's drawn it should be good up to 50W with the right heatsink.
It's also very forgiving in terms of component values and (probably) layout. I've messed around in SPICE, and it takes real work to make it misbehave. You can even mess up the matching of the LTP transistors quite badly without it throwing a fit. It also has a >70 degree phase margin in simulations and would probably do fine with a lower Miller capacitance if someone wants faster performance. I've tried it with 8ohm and 6ohm speakers, and based on simulations it should have no problem at all with 4ohm as long as you're staying within a reasonable power (50W). The gain is 23x (27dB), which is a bit low for regular line level. You could probably bump it up a bit, but I'd probably recommend a pre-amp instead. I haven't checked the stability with a higher gain.
This design has been built and sounds and measures well. Audiophile quality? Probably not, but good enough to "open up" music I've listened to many times before and letting me discover new details.
I'll share the schematic and also a Github repo with all the design and simulation files, along with some ideas on how to build and test it. If you're a beginner, feel free to try it or just borrow ideas and inspiration. And if you're an experienced designer, I'm happy to listen to ideas for improvement. You can even clone the repo and send me a pull request if you want to contribute. But please be gentle! 🙂
There are a few things I'd like to change when I get a chance. The pot on the long tail can be replaced with fixed resistors and the terminal block for the speakers on the middle of the board is awkward. But it's buildable and works well in its current form. You could (and probably should) add speaker protection and maybe a preamp and some tone controls.
The repo: https://github.com/prydin/classab-amp-mosfet
I hope you'll find my humble contribution valuable in some way. And be gentle on me!
[EDIT: Updated the schematic with a protection diode for the VAS to avoid disasters... Also removed the DC offset pot, since it doesn't do much due to the current mirror]
Alpha Nirvana 39w 8ohm Class A Amp
- By xrk971
- Solid State
- 3850 Replies
Hugh has been doodling on LTSpice and he came up with something really extraordinary: a 43% efficient SE Class A amp that can drive 39w into an 8ohm load with the usual Aksa-approved harmonic profile and low phase shift. The amp uses only 6 bog-standard actives and employs the excellent Aksa Lender front end to drive what seems like standard complementary MOSFET output stage using the venerable and easy to find IRFP240 and IRFP9240 outputs. However, it is not a push-pull amp though, but operates in SE Class A with an active CCS controlled by a cleverly wired PNP CCS controller. Please note that this active CCS is no longer based on the Pass Aleph topology but a PNP-controlled P-channel with symmetric sense resistors. The amp should really be called an Aksa Lender Nirvana.
So we have 4x TO-92's, and two TO-247 MOSFETs. Together, with only a +/-27v supply, they combine to make 39w into 8ohms with a predicted 0.019% THD AT 12w, and of course, always dominant H2 and a monotonically decreasing higher order harmonics. Output impedance is predicted to be less than 50mOhm at 12w into 8ohms at 1kHz and DF is 160. Quite a powerful amp given the rather low 27v rails. 27v rails happen to be what you get when you use an SLB PSU with a 22v trafo like an Antek AS-3222. Gain is 28.5dB, and phase shift is only 5.3deg at 20kHz.
Here is the rough schematic from LTSpice:
More detailed analyses and sims to come...
Later to be followed with the usual P2P vero-build, and then hopefully, a real PCB verification build and full measurements.
Enjoy!
A huge thank you to Hugh for continuing to give us these gems!
Edit Sept 21, 2023: Looking for Cliffs Notes on the BOM and some and hints on what parts to use etc by Voiceofposeidon here: https://www.diyaudio.com/community/...8ohm-class-a-amp.344540/page-107#post-6920076
Edit May 25, 2020: detailed O-scope max power clipping tests by AndyR using his 4-ohm variant Alpha Nirvana with +/-21v rails:
Alpha Nirvana 39w 8ohm Class A Amp
Short story - good for 34W into 2.1ohms loads! Not bad for true Class A amp (cannot ever go into Class AB - it simply softly clips when pushed).
Edit Oct 31, 2019: latest version 2 schematic of amp
Predicted FFT with v2 for 2.83Vrms into 8ohm, THD=0.0039%:
And if we increase power to about 12.5w into 8ohm, we still see a nice monotonically decreasing harmonic distortion profile. THD is now about 0.016%:
Edit Nov 27, 2019: Measured max output before clipping is 51.6vpp into 8ohms, or about 41.6w into 8ohms. This is with +/-28.5v rails.
Edit Nov 29, 2019 - Grounding scheme schematic (post 279):
Produces background noise FFT like this:
Some measurements at 3.16vrms into 10ohms with a Cayin N3 DAP as 1kHz osc source, obtained 0.0041% THD and mostly 2nd and 3rd harmonic:
GB thread for this amp here:
Alpha Nirvana 39W SE Class A Amplifier GB
Tips and tools on how to do professional clean looking SMT/SMD soldering:
Alpha Nirvana 39w 8ohm Class A Amp
Edit Dec 14, 2019: BOM in easy to read .XLSX format: https://www.diyaudio.com/forums/att...8ohm-class-amp-alpha-nirvana_bom_001-xlsx-zip
Mouser Shopping Cart for BOM here. Do not modify cart - please save to your own shopping cart as a new project before changing.
Edit Jan. 3, 2020: please note that the Mouser shopping cart above needs to have parts for snubber boards increased by 2x as there are parts for 1 board only. The BOM is for one amp board so needs to be doubled for stereo. Double following: (R1001, R1002, C1002, V1001)
Edit Dec 26, 2019: AndyR did a lot of due dilligence to put together a very nice BOM for both the 8ohm and 4ohm versions of this amp here:
Alpha Nirvana 39w 8ohm Class A Amp
Thank you, AndyR!
Edit Apr 24, 2020 - Dual Monobloc Connection Diagram is using SLB and SFP boards:
As built schematic verified and tested to work:
Edit Apr 19, 2022: beautiful build by Steve (Sledwards12375):
Edit July 12, 2024: @AKSA said in this post that 2.2A quiescent current is needed for 4ohm variant of this amp. So size your trafo accordingly.
So we have 4x TO-92's, and two TO-247 MOSFETs. Together, with only a +/-27v supply, they combine to make 39w into 8ohms with a predicted 0.019% THD AT 12w, and of course, always dominant H2 and a monotonically decreasing higher order harmonics. Output impedance is predicted to be less than 50mOhm at 12w into 8ohms at 1kHz and DF is 160. Quite a powerful amp given the rather low 27v rails. 27v rails happen to be what you get when you use an SLB PSU with a 22v trafo like an Antek AS-3222. Gain is 28.5dB, and phase shift is only 5.3deg at 20kHz.
Here is the rough schematic from LTSpice:
More detailed analyses and sims to come...
Later to be followed with the usual P2P vero-build, and then hopefully, a real PCB verification build and full measurements.
Enjoy!
A huge thank you to Hugh for continuing to give us these gems!
Edit Sept 21, 2023: Looking for Cliffs Notes on the BOM and some and hints on what parts to use etc by Voiceofposeidon here: https://www.diyaudio.com/community/...8ohm-class-a-amp.344540/page-107#post-6920076
Edit May 25, 2020: detailed O-scope max power clipping tests by AndyR using his 4-ohm variant Alpha Nirvana with +/-21v rails:
Alpha Nirvana 39w 8ohm Class A Amp
Short story - good for 34W into 2.1ohms loads! Not bad for true Class A amp (cannot ever go into Class AB - it simply softly clips when pushed).
Edit Oct 31, 2019: latest version 2 schematic of amp
Predicted FFT with v2 for 2.83Vrms into 8ohm, THD=0.0039%:
And if we increase power to about 12.5w into 8ohm, we still see a nice monotonically decreasing harmonic distortion profile. THD is now about 0.016%:
Edit Nov 27, 2019: Measured max output before clipping is 51.6vpp into 8ohms, or about 41.6w into 8ohms. This is with +/-28.5v rails.
Edit Nov 29, 2019 - Grounding scheme schematic (post 279):
Produces background noise FFT like this:
Some measurements at 3.16vrms into 10ohms with a Cayin N3 DAP as 1kHz osc source, obtained 0.0041% THD and mostly 2nd and 3rd harmonic:
GB thread for this amp here:
Alpha Nirvana 39W SE Class A Amplifier GB
Tips and tools on how to do professional clean looking SMT/SMD soldering:
Alpha Nirvana 39w 8ohm Class A Amp
Edit Dec 14, 2019: BOM in easy to read .XLSX format: https://www.diyaudio.com/forums/att...8ohm-class-amp-alpha-nirvana_bom_001-xlsx-zip
Mouser Shopping Cart for BOM here. Do not modify cart - please save to your own shopping cart as a new project before changing.
Edit Jan. 3, 2020: please note that the Mouser shopping cart above needs to have parts for snubber boards increased by 2x as there are parts for 1 board only. The BOM is for one amp board so needs to be doubled for stereo. Double following: (R1001, R1002, C1002, V1001)
Edit Dec 26, 2019: AndyR did a lot of due dilligence to put together a very nice BOM for both the 8ohm and 4ohm versions of this amp here:
Alpha Nirvana 39w 8ohm Class A Amp
Thank you, AndyR!
Edit Apr 24, 2020 - Dual Monobloc Connection Diagram is using SLB and SFP boards:
As built schematic verified and tested to work:
Edit Apr 19, 2022: beautiful build by Steve (Sledwards12375):
Edit July 12, 2024: @AKSA said in this post that 2.2A quiescent current is needed for 4ohm variant of this amp. So size your trafo accordingly.
Attachments
MarkAudio Okapi - Alpair 7MS build
- By umea101
- Full Range
- 14 Replies
I wanted to share here my experience of building the Mark Audio Okapi with Alpair 7MS designed by Scott Lindgren. I was looking for a relatively compact (i.e. narrow) loudspeaker that I could use in my home office. The plan is to use it with an Audio Note Kits "Virtuoso" PP EL84 Headphone/Speaker amplifier that I built a few years ago. I am currently using a pair of Fostex FE83sol in tiny cabinets and I wanted to see if I could do better than that. After reading many posts in this forum I decided to give a self build a go.
Since I do not have a workshop I ordered my plywood (18mm baltic birch) pre-cut online from cutmy.co.uk. I could even specify the circular cut-outs for the drivers and the reflex tube. Here is what came in the package:
Since I do not have a workshop I ordered my plywood (18mm baltic birch) pre-cut online from cutmy.co.uk. I could even specify the circular cut-outs for the drivers and the reflex tube. Here is what came in the package:
Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter
- By iancanada
- Digital Line Level
- 13399 Replies
People keep talking too much about jitter issues, but did less to make some kind of improvement. I decided trying to do something real – a working asynchronous I2S FIFO.
Before I go any further, I need to make something clear in advance:
1. FIFO is widely believed as one of the final methods to deal with jitter problems. But the asynchronous FIFO itself is just a technology which could provide a logic function to isolate the two clock domain. That means, for an I2S stream, digital audio data could pass through without any modification but the input clock was blocked and replaced with the new one. The new clock is totally independent from the old one except they should have the similar frequency. The FIFO logic itself does not influence the sound quality;
2. What really makes it sound better (or even worse) is the low jitter secondary clock. For example, if we have a new clock after the FIFO which comes with one digit ps jitter(RMS), we should get much better sound quality than before (the jitter level of the master clock from DIR chip usually around 50ps(RMS) level above corner frequency). So, we should pay more attention on the secondary clock and related interface. Everything connected to secondary clock has to be very carefully to deal with; otherwise new additive jitter will be introduced;
3. The size of the FIFO memory should big enough to meet overflow or empty time caused by the worst case of i2s input clock, but still has to be carefully selected to get the balance between the delay time caused by the working depth(usually half full) of the FIFO;
4. FIFO with low jitter secondary clock could only reduce the play back jitter for an audio DAC, but has nothing to do with the sampling jitter. I don’t have any idea if a CD was reordered with poor clock of the ADC.
The main logic functions could be achieved by a FPGA/CPLD chip together with a megabit SRAM. But the clock section has to use specialized clock/timing circuit, because the jitter performance of the output of FPGA/CPLD are far from what we want.
Below is the possible block diagram of this I2S FIFO project:
https://github.com/iancanada/DocumentDownload
https://twitter.com/iancanadaTT
FifoPi Q7 Jan.12,2023 update https://github.com/iancanada/DocumentDownload/blob/master/FifoPi/FifoPiQ7/FifoPiQ7Manual.pdf
FifoPiQ7_0 by Ian, on Flickr
Before I go any further, I need to make something clear in advance:
1. FIFO is widely believed as one of the final methods to deal with jitter problems. But the asynchronous FIFO itself is just a technology which could provide a logic function to isolate the two clock domain. That means, for an I2S stream, digital audio data could pass through without any modification but the input clock was blocked and replaced with the new one. The new clock is totally independent from the old one except they should have the similar frequency. The FIFO logic itself does not influence the sound quality;
2. What really makes it sound better (or even worse) is the low jitter secondary clock. For example, if we have a new clock after the FIFO which comes with one digit ps jitter(RMS), we should get much better sound quality than before (the jitter level of the master clock from DIR chip usually around 50ps(RMS) level above corner frequency). So, we should pay more attention on the secondary clock and related interface. Everything connected to secondary clock has to be very carefully to deal with; otherwise new additive jitter will be introduced;
3. The size of the FIFO memory should big enough to meet overflow or empty time caused by the worst case of i2s input clock, but still has to be carefully selected to get the balance between the delay time caused by the working depth(usually half full) of the FIFO;
4. FIFO with low jitter secondary clock could only reduce the play back jitter for an audio DAC, but has nothing to do with the sampling jitter. I don’t have any idea if a CD was reordered with poor clock of the ADC.
The main logic functions could be achieved by a FPGA/CPLD chip together with a megabit SRAM. But the clock section has to use specialized clock/timing circuit, because the jitter performance of the output of FPGA/CPLD are far from what we want.
Below is the possible block diagram of this I2S FIFO project:
https://github.com/iancanada/DocumentDownload
https://twitter.com/iancanadaTT
FifoPi Q7 Jan.12,2023 update https://github.com/iancanada/DocumentDownload/blob/master/FifoPi/FifoPiQ7/FifoPiQ7Manual.pdf
FifoPiQ7_0 by Ian, on FlickrAttachments
Schematic request: Alesis BRC (Big Remote Control)
I looked around and can't find a good place to file this thread, so if I missed something, Mods, please feel free to relocate.
I am about to purchase an Alesis BRC which will (hopefully) control my HD24 [24-track hard disc recorder]. It was originally designed to control many ADAT machines, daisy chained together. ADAT uses SVHS tape for audio recording. Anyway the HD24 is 24 tracks od digital recording onto hot-swappable hard drives. But since access is orders of magnitude faster on the HD than spooling tape, there can be sync issues... (it CAN allegedly daisy chain HD24s to provide 48+ tracks, up to 128 max or something silly like that)
I have the Alesis service manual, and it indicates an appendix for the schematics, but they are not there. It must have been a separate file or insert added at the repair facility. I do have the "confidential" service tech final testing procedures at the end of the copy of the manual I have so it seems to be "complete".
Please have a look around and see if you have one or can point me to an online source. I can't find it anywhere and I was digging pretty deep...
Thanks in advance for any help!
I am about to purchase an Alesis BRC which will (hopefully) control my HD24 [24-track hard disc recorder]. It was originally designed to control many ADAT machines, daisy chained together. ADAT uses SVHS tape for audio recording. Anyway the HD24 is 24 tracks od digital recording onto hot-swappable hard drives. But since access is orders of magnitude faster on the HD than spooling tape, there can be sync issues... (it CAN allegedly daisy chain HD24s to provide 48+ tracks, up to 128 max or something silly like that)
I have the Alesis service manual, and it indicates an appendix for the schematics, but they are not there. It must have been a separate file or insert added at the repair facility. I do have the "confidential" service tech final testing procedures at the end of the copy of the manual I have so it seems to be "complete".
Please have a look around and see if you have one or can point me to an online source. I can't find it anywhere and I was digging pretty deep...
Thanks in advance for any help!
Inconsistent measurements
A couple days ago I measured a set of speakers (in-room). After a few minutes I repeated the measurement with the exact same settings (maybe apart from signal level and mic sensitivity), without changing the placement of mic and speakers. To my surprise both measurements were quite different. Today I repeated the process, and again, two measurements a couple minutes apart show very different results.
Measurement setup
Amp: Hypex NCore based (AudioPhonics MPA-S250NC)
Audio Interface: Behringer UMC22
Mic: Dayton EMM-6
Software: REW 5.31.3
Driver: ASIO4All 2.16
Today I loaned an Audio Interface from a friend of mine, a Focusrite Scarlett 8i6. I was hoping to eliminate this link in the chain. Below are a few measurements.
As can be seen, there's much less variance between these measurements. But still over 4dB, which seems way too much to me.
Has anyone else had issues with inconsistency in measurements?
What whould be the most likely cause?
Measurement setup
Amp: Hypex NCore based (AudioPhonics MPA-S250NC)
Audio Interface: Behringer UMC22
Mic: Dayton EMM-6
Software: REW 5.31.3
Driver: ASIO4All 2.16
Today I loaned an Audio Interface from a friend of mine, a Focusrite Scarlett 8i6. I was hoping to eliminate this link in the chain. Below are a few measurements.
As can be seen, there's much less variance between these measurements. But still over 4dB, which seems way too much to me.
Has anyone else had issues with inconsistency in measurements?
What whould be the most likely cause?
For Sale 2 Pairs of TW29TXN-B
I am selling 2 pairs of TW29TXN-B satoti tweeters.
Selling as i am moving to be tweeters
Looking to get $300 per pair
Buyer Pays shipping and paypal
Selling as i am moving to be tweeters
Looking to get $300 per pair
Buyer Pays shipping and paypal
SB Acoustics SB20FRPC30-8 (8" Fullrange Cheap Monster II)
- By nandappe
- Full Range
- 825 Replies
Attachments
F5m kit
- By Nelson Pass
- Pass Labs
- 2895 Replies
Presenting the documentation for the F5m appearing shortly in the store.
The Essentials kit consists of the Jfets and Mosfets plus two channels of pc board and 1 power supply pc board.
The Completion kit is everything else except chassis, power transformer, rear panel connectors/switch/ac inlet.
The kit is designed around several chassis available in the store, but is fairly agnostic.
Attached is the article I wrote for this project, and this is the support thread.
2/11/2024 After testing by member 6L6, I revised the power supply layout and made an additional
note about the power supply thermistors with higher output stage biasing. The revised article is labeled
R1, and both are attached below.
Update Alert: It turns out that the insulators we bought were not very insular. Not a disaster in general
but a problem if your heat sinks are bare metal. Different pads are available for this.
See the details in post 1,003 of this thread.
Also note 4/21/2024 revision of the power supply board.
EDIT: Build Guide here - https://guides.diyaudio.com/Guide/F5M+Amplifier/29?lang=en
The Essentials kit consists of the Jfets and Mosfets plus two channels of pc board and 1 power supply pc board.
The Completion kit is everything else except chassis, power transformer, rear panel connectors/switch/ac inlet.
The kit is designed around several chassis available in the store, but is fairly agnostic.
Attached is the article I wrote for this project, and this is the support thread.
2/11/2024 After testing by member 6L6, I revised the power supply layout and made an additional
note about the power supply thermistors with higher output stage biasing. The revised article is labeled
R1, and both are attached below.
Update Alert: It turns out that the insulators we bought were not very insular. Not a disaster in general
but a problem if your heat sinks are bare metal. Different pads are available for this.
See the details in post 1,003 of this thread.
Also note 4/21/2024 revision of the power supply board.
EDIT: Build Guide here - https://guides.diyaudio.com/Guide/F5M+Amplifier/29?lang=en
BOSS CE-4800D Parts or (Schematic)?
C/E/X PA Flat to 30 (FT30) PA TH Awesomeness
- By CRESCENDO
- Subwoofers
- 1050 Replies
This thread is a continuation of woody1's thread (flat to 40Hz) which can be found here: http://www.diyaudio.com/forums/subwoofers/170749-15-tapped-horn-rcf.html
Epa, Xoc1 and others have been contributing their time and effort in attempt to help me reach my goal: Flat to 30Hz with as much clean output as possible - XTRA points for breaking physics and keeping it small. Heh.
We have found 15" drivers are limited by xmax far before maximum power is reached.
Here's where we left off:
My REAL 6 Fold mod (I meant to post) @ 2.83V
30Hz = 98.29
40Hz = 98.48
0.19 dB difference, so step from 30 to 40Hz is 4.38 dB less AND 2.12 dB more output at 30Hz
What's your take on this version?
Must they (post 73) be used in a cardioid sub array? Will I/we loose any performance if they're not?
Welcome 🙂
Any others: feel free to post your design if you believe it betters any of these and fits the goal posted above. Many thanks!
Justin
Epa, Xoc1 and others have been contributing their time and effort in attempt to help me reach my goal: Flat to 30Hz with as much clean output as possible - XTRA points for breaking physics and keeping it small. Heh.
We have found 15" drivers are limited by xmax far before maximum power is reached.
Here's where we left off:
My REAL 6 Fold mod (I meant to post) @ 2.83V
30Hz = 98.29
40Hz = 98.48
0.19 dB difference, so step from 30 to 40Hz is 4.38 dB less AND 2.12 dB more output at 30Hz
What's your take on this version?
restriction is not to bad because of the neodinium magnet.
i designed the post 73 th for the use in a cardroid sub aray.
this is why its symetric.
i like xco1 model 2,its a easier bild but for me a little to big.
i wil work this weekend on it to give you al the details😉
meanwile here are some designs,most of them are posted here.to make your choice more diffecult😛
Must they (post 73) be used in a cardioid sub array? Will I/we loose any performance if they're not?
(Referring to post 73)
justin ,we need to make a new topic,because this has no longer anything to do with woodys design ,
Welcome 🙂
Any others: feel free to post your design if you believe it betters any of these and fits the goal posted above. Many thanks!
Justin
Is HM3S a Goldmund clone?
- By year98
- Solid State
- 11 Replies
https://www.ebay.com/itm/195785024138
This uses k1058/j162, the circuit diagram looks like a goldmund clone.
But why does this kit have a vbe multiplier? Does it work?
I'm new to vbe multiplier on an amplifier using lateral MOSFET.
For Sale KEF 104/2 Crossovers, Recapped
- By TheFinisher
- Swap Meet
- 8 Replies
Fully recapped with the Falcon Acoustics Alcap capacitors ( £137 )
Removed from my fully working speakers
£200 + shipping ( I’m uk based. )
Removed from my fully working speakers
£200 + shipping ( I’m uk based. )
Learning assistance
- By tapepath1
- Tubes / Valves
- 16 Replies
Hello,
I wonder if someone could suggest a good source of information, either in print form or online is fine, for understanding a particular negative feedback circuit as it applies to shaping an EQ response. In other words I would like to learn how it functions (I have a good idea of the basics) and what the mathematics are for determining component values and how to change them to achieve different requirements. This is the circuit I'm interested in:
I wonder if someone could suggest a good source of information, either in print form or online is fine, for understanding a particular negative feedback circuit as it applies to shaping an EQ response. In other words I would like to learn how it functions (I have a good idea of the basics) and what the mathematics are for determining component values and how to change them to achieve different requirements. This is the circuit I'm interested in:
CamillaDSP - Cross-platform IIR and FIR engine for crossovers, room correction etc
- PC Based
- 6077 Replies
I would like to announce CamillaDSP, a general purpose tool for routing and filtering sound. It can be used for example for building crossovers for active speakers, or for performing room correction.
You can find the source code here: GitHub - HEnquist/camilladsp
The documentation for all published versions can be found here: CamillaDSP
There is a second repository for configuration help here: GitHub - HEnquist/camilladsp-config: Help for setting up CamillaDSP, example config files etc
Quick summary
I have been using BruteFIR for crossovers for quite some time, but there were two main things I wanted to improve upon. Firstly BruteFIR only supports FIR filters, and I wanted the ability to also use BiQuad without having to make an overly complicated setup. Secondly when BruteFIR encounters a buffer underrun it always exits with a "broken pipe" error instead of just trying again. This can get somewhat annoying. I also thought that the BruteFIR configuration is unnessecarily complicated.
I have also been using the excellent tool EqualizerAPO that does all I want, but it's for Windows only.
When using Alsa for both input and output, CamillaDSP can work almost as a drop-in replacement for BruteFIR. I run a 2048 tap stereo 2-way crossover at 44.1kHz, and this consumes less than 2% of a single cpu core on my HTPC (dual core Intel Skylake).
To help with configuration CamillaDSP checks the configuration and tries to give helpful error messages when there is a problem. In addition there is a Python script to visualize the whole pipeline from a config file.
Sample output:
To try it, download a pre-built binary for your system from the "Releases" page:. Click "Assets" to view the available files.
Instead of using a pre-built binary it can also be built from source. The "Cargo" tool makes this very easy as it will download and compile all dependencies automatically. See more instructions in the README.
You can find the source code here: GitHub - HEnquist/camilladsp
The documentation for all published versions can be found here: CamillaDSP
There is a second repository for configuration help here: GitHub - HEnquist/camilladsp-config: Help for setting up CamillaDSP, example config files etc
Quick summary
- For Linux, macOS and Windows
- Written in Rust
- IIR filters (BiQuad)
- FIR filters (Convolution via FFT)
- Built-in sample rate converter
- Filters can be chained freely
- Flexible routing
- Alsa, PulseAudio, Wasapi, CoreAudio, File and stdio input/output
- Simple YAML configuration
- All calculations done with 64-bit floats
I have been using BruteFIR for crossovers for quite some time, but there were two main things I wanted to improve upon. Firstly BruteFIR only supports FIR filters, and I wanted the ability to also use BiQuad without having to make an overly complicated setup. Secondly when BruteFIR encounters a buffer underrun it always exits with a "broken pipe" error instead of just trying again. This can get somewhat annoying. I also thought that the BruteFIR configuration is unnessecarily complicated.
I have also been using the excellent tool EqualizerAPO that does all I want, but it's for Windows only.
When using Alsa for both input and output, CamillaDSP can work almost as a drop-in replacement for BruteFIR. I run a 2048 tap stereo 2-way crossover at 44.1kHz, and this consumes less than 2% of a single cpu core on my HTPC (dual core Intel Skylake).
To help with configuration CamillaDSP checks the configuration and tries to give helpful error messages when there is a problem. In addition there is a Python script to visualize the whole pipeline from a config file.
Sample output:
To try it, download a pre-built binary for your system from the "Releases" page:. Click "Assets" to view the available files.
Instead of using a pre-built binary it can also be built from source. The "Cargo" tool makes this very easy as it will download and compile all dependencies automatically. See more instructions in the README.
