Older kicker kx1200.1 Powers on but doesn't get loud with pictures
- By Jasonsayre
- Class D
- 0 Replies
LRDDMC Loudspeaker Resistor Drive Distortion Measurement Challenge
Nobody wants to know if you hear distortion.
But
Do you measure distortion?
I thought about what a measurement experiment could look like so that the person measuring can directly experience what they are currently doing and achieving.
Do you have a speaker? Good!
Have you ever measured the frequency response of your speaker? Good!
Can you connect a line directly to a transducer in it (leave out the crossover)? Good!
Find a resistor with 20R! Don't worry about the power performance of this resistor! Just keep explosives, your beautiful toddler, your cat... away! 10 Watts is what i use. That's plenty and certainly a lot more than my speaker can handle.
Complete your usual measurement setup.
Carry out a measurement at a very moderate volume. Only the transducer in the box, directly connected to the amplifier. [1]
Save this measurement to overlay. [1]
Then insert the 20R resistor. In series to the transducer. Carry out a second measurement. Increase the volume to approximately the same sound pressure level. [3]
This is all about distortion. So RTFM until you have two distortion charts.
[4] One connected directly and one with the 20R in series.
If you do not see a difference in D3 ask here for help.
This was done at 0,5 Volts at the transducer:
No need to blast your speaker!
[1] yellow is the fundamental directly connected (0R)
[2] Same setup, just disconnected speaker. Noise...
[3]
green is with 20R in series.
yellow is directly connected (from [1])
[4]
D3o (white) is directly connected (0R)
D3 (red) is with 20R in series
20240108 Edit 1:
I am extremely disappointed by the fact that no one is taking measurements here on diyAudio. There are only theoretical heroes here who type more or less gross nonsense with their keyboard.
20240108 Edit 2:
User >OllBoll< on diyAudio was the first measuring "it".
https://www.diyaudio.com/community/threads/hypex-ncore.190434/page-384#post-4095122
He was cited on a German forum on
12.09.2023, 16:47
9 years (nine years !) later, because there was nobody on the whole internet measuring "it". Now that
Tenson< joined,
https://www.diyaudio.com/community/...ortion-measurement.402566/page-9#post-7558653
we are 3. Please be the 4th ;-)
20240110 Edit 3:
tmuikku< joined (#40), we are 4. please be the 5th ;-)
But
Do you measure distortion?
I thought about what a measurement experiment could look like so that the person measuring can directly experience what they are currently doing and achieving.
Do you have a speaker? Good!
Have you ever measured the frequency response of your speaker? Good!
Can you connect a line directly to a transducer in it (leave out the crossover)? Good!
Find a resistor with 20R! Don't worry about the power performance of this resistor! Just keep explosives, your beautiful toddler, your cat... away! 10 Watts is what i use. That's plenty and certainly a lot more than my speaker can handle.
Complete your usual measurement setup.
Carry out a measurement at a very moderate volume. Only the transducer in the box, directly connected to the amplifier. [1]
Save this measurement to overlay. [1]
Then insert the 20R resistor. In series to the transducer. Carry out a second measurement. Increase the volume to approximately the same sound pressure level. [3]
This is all about distortion. So RTFM until you have two distortion charts.
[4] One connected directly and one with the 20R in series.
If you do not see a difference in D3 ask here for help.
This was done at 0,5 Volts at the transducer:
No need to blast your speaker!
[1] yellow is the fundamental directly connected (0R)
[2] Same setup, just disconnected speaker. Noise...
[3]
green is with 20R in series.
yellow is directly connected (from [1])
[4]
D3o (white) is directly connected (0R)
D3 (red) is with 20R in series
20240108 Edit 1:
I am extremely disappointed by the fact that no one is taking measurements here on diyAudio. There are only theoretical heroes here who type more or less gross nonsense with their keyboard.
20240108 Edit 2:
User >OllBoll< on diyAudio was the first measuring "it".
https://www.diyaudio.com/community/threads/hypex-ncore.190434/page-384#post-4095122
He was cited on a German forum on
12.09.2023, 16:47
9 years (nine years !) later, because there was nobody on the whole internet measuring "it". Now that
Tenson< joined,
https://www.diyaudio.com/community/...ortion-measurement.402566/page-9#post-7558653
we are 3. Please be the 4th ;-)
20240110 Edit 3:
tmuikku< joined (#40), we are 4. please be the 5th ;-)
ELEKIT TU-8800 SET AMP
Available Now....
TU-8800 $1185 (stock version)
TU-8800 $1,785 (Lundahl Version)
Takman REX50G 2% Carbon Resistor (85 PCS) $65.00
Mundorf Supreme Silver Gold 0.01 X 2 + 0.1 X 2 $150
Gold Lion - Matched Pair KT88 X 2 + 12AT7/B739 X 2 $185
TKD 2CP601S $65
The Lundhal + PCB + HV + Hardware is $645
https://www.diyaudio.com/forums/elekit/353407-inexpensive-tube-set-tu-8800-a.html#post6177418
● Rated output: 12.5W + 12.5W (KT88-HIGH mode / UL connection THD 10%)
● Rated input: 360mV
● Residual noise: 90μV (IHF-A)
● Frequency characteristics: 12Hz to 55kHz (-3dB)
● Input impedance: 50kΩ
● Output impedance: 4 to 6.3Ω, 8 to 16Ω (switched by the switch on the back)
● Input terminal: LINE x 2 (LINE1, LINE2): RCA jack 3.5mm stereo mini jack (uses both LINE2 and cuts LINE2 when plugged in)
● Output terminal: Speaker output terminal: Gold-plated screw terminal (banana plug can be used) Headphone terminal: 6.3mm headphone jack
● Power supply voltage: AC120 / 200V 50 / 60Hz (3P inlet)
● Power consumption: 95W
● Body dimensions: W350 x H204 x D324mm (including protrusions)
● Body weight: approx. 12kg (without power cord)
IT SHOULD BE 7581 (NOT 7591)
OPTION: Lundahl OPT
TU-8800 $1185 (stock version)
TU-8800 $1,785 (Lundahl Version)
Takman REX50G 2% Carbon Resistor (85 PCS) $65.00
Mundorf Supreme Silver Gold 0.01 X 2 + 0.1 X 2 $150
Gold Lion - Matched Pair KT88 X 2 + 12AT7/B739 X 2 $185
TKD 2CP601S $65
The Lundhal + PCB + HV + Hardware is $645
https://www.diyaudio.com/forums/elekit/353407-inexpensive-tube-set-tu-8800-a.html#post6177418
● Rated output: 12.5W + 12.5W (KT88-HIGH mode / UL connection THD 10%)
● Rated input: 360mV
● Residual noise: 90μV (IHF-A)
● Frequency characteristics: 12Hz to 55kHz (-3dB)
● Input impedance: 50kΩ
● Output impedance: 4 to 6.3Ω, 8 to 16Ω (switched by the switch on the back)
● Input terminal: LINE x 2 (LINE1, LINE2): RCA jack 3.5mm stereo mini jack (uses both LINE2 and cuts LINE2 when plugged in)
● Output terminal: Speaker output terminal: Gold-plated screw terminal (banana plug can be used) Headphone terminal: 6.3mm headphone jack
● Power supply voltage: AC120 / 200V 50 / 60Hz (3P inlet)
● Power consumption: 95W
● Body dimensions: W350 x H204 x D324mm (including protrusions)
● Body weight: approx. 12kg (without power cord)
IT SHOULD BE 7581 (NOT 7591)
OPTION: Lundahl OPT
Online Calculator or Freeware Program for Power Supply Design?
- By noacronym
- Electronic Design
- 7 Replies
Attachments
Martin Logan Ethos 2024 Active (DIY)
- By syddk
- Planars & Exotics
- 10 Replies
Just finished a small project adding a Hypex NC500MP under each speaker to make them active. Also had the cabinets spray painted in satin gray polyurethane furniture paint. I think it looks more up to date 2024-ish. By the way, the hypex does quite good driving the ESL load. I had a dialogue wiht Hypex (nice people!), and they confirmed that it would not be a problem with the ESL load. This is a point where Hypex differs from Icepower. Icepower would probably have a challenge with the capacitive load. Anyway, now my Ethos are fully active with hypex driving the esl's and icepower for the subs. Works nice 😉
What do you think?
What do you think?
Discussion: The relationship between the Fosgate PR-250 and the Pioneer AD-360
I recently acquired a Pioneer AD-360 from the late Jim Fosgates estate. At first, I was hopeful that he threw some secret sauce in this one and i'd get to be the only one to enjoy that. Turns out he didn't. In fact, it didn't even work. So my next guess was a friend left it with him for repair because 'My buddy Jim knows amps' is probably how the rationale went.
So I went looking for a schematic. But I was too cheap to buy the service manual. Then I started looking up part numbers. The part numbers led to a thread here
The drawing note on the PR-250 schematic led me down a rabbit hole as not only was I able to use the PR-250 schematic to service my amp, it bears the 'GM160' stamp!
The drawing note:
The board stamp on my AD-360:
At this point i'm just MADE of questions. Both of these amplifiers were released around the same time. It's sitting in Jim's house. One board is referenced in another's drawing. They're both 'Made in the USA' which is not common for Pioneer electronics of the era.
What was the relationship between Jim Fosgate and this product?
Did Jim OEM the AD-360 for Pioneer?
Did Pioneer License the design from Fosgate?
Did Pioneer OEM the PR-250 for Jim and Jim added the processing in house?
Was the 'GM160' a build house design both Pioneer and Fosgate custom tailored for their models?
Another interesting note: I have 2 of these amplifiers. Jim's model has no solder mask and the unit bears no serial number or warranty sticker but my other model does!
So I went looking for a schematic. But I was too cheap to buy the service manual. Then I started looking up part numbers. The part numbers led to a thread here
The drawing note on the PR-250 schematic led me down a rabbit hole as not only was I able to use the PR-250 schematic to service my amp, it bears the 'GM160' stamp!
The drawing note:
The board stamp on my AD-360:
At this point i'm just MADE of questions. Both of these amplifiers were released around the same time. It's sitting in Jim's house. One board is referenced in another's drawing. They're both 'Made in the USA' which is not common for Pioneer electronics of the era.
What was the relationship between Jim Fosgate and this product?
Did Jim OEM the AD-360 for Pioneer?
Did Pioneer License the design from Fosgate?
Did Pioneer OEM the PR-250 for Jim and Jim added the processing in house?
Was the 'GM160' a build house design both Pioneer and Fosgate custom tailored for their models?
Another interesting note: I have 2 of these amplifiers. Jim's model has no solder mask and the unit bears no serial number or warranty sticker but my other model does!
SET Friendly MTM, Seas ER18RNX and 27TDFC
I built this in 2007, with a lot of help here from Jay and Zaph particularly with the crossover. I thank these guys most sincerely!
Design was constrained by WAF to about 8.5 inches wide, about 12 inches deep and 1 metre high, also by the amp, my 45 parallel SET giving 3.5 watts (note the decimal point). Don't query the amp unless you've heard a 45 SET, if you have you will understand. Room is 18ft x 14ft.
The speaker is about 42 litres, bass reflex to give good sensitivity.
The Q of the bass driver was calculated allowing for amp Zout, giving Qts 0.51 quite high. This made bass alignment a bit of a problem; the ideal volume for a standard alignment became massive. But it was overcome with use of WINisd. With my volume it was not possible to avoid a hump in the bass, but tuning the port to 30Hz got the hump to below 1dB. Group delay was under 10mS at 40Hz (Zaph's criterion), and if I remember, the peak in group delay was moved to quite a low frequency and was not too massive. In fact this is very much Zaph's 'lean and low' tuning; low is obvious, and lean I take to mean removing or minimising the hump at roughly 80 to 100Hz.
Crossover was very similar to Zaph's one for his MTM with Vifa woofers and 27TDFC, virtually as Jay's suggestion; very simple:
Woofers 1.35mH, 40uF
Tweeter 1.9 ohm series R, 12uF, 0.39mH
The L on the woofers adjusted by ear for BSC, starting value 1.4mH was very good.
Tweeter C was adjusted after SPL measurement to reduce a slight dip in the upper crossover region.
The result?
Superb.
Bass is very good, adequate quantity, reasonable depth, very good quality; nothing boomy; tight, tuneful, fast. I had expected to want to try different port lengths, or straws or damping, but once I heard it I told myself, do not mess with anything! (I've messed electronics up in the past and never got back to the best).
Overall, sound is tuneful, fine tonality, good rhythms, excellent leading edges (says a critical friend who loves leading edges and dynamics); superb vocals. Highly musical. Just seems to do lots of things right in a way that you don't notice them, they disappear.
I like the combination of amp and speakers a whole lot, and I'd put it this way.
In hifi, you might have decent hifi sound.
Go a level higher, and it sounds like better hifi, you notice the hifi things more.
But at a higher level still, I find it sounds less like hifi; I don't notice the hifi things, they go away, leaving a very natural presentation.
These speakers are getting close to doing that.
Liked a lot by hifi addict friends; a Naim addict dynamics freak says they have some dynamics and rhythms (and he's critical, blunt with it, like Craig Revel Horwood, for my own good, and he knows his stuff).
The system does not sound underpowered in any way; for one thing the amp sounds more powerful than my 300B SETs of twice the power. Definitely all the volume I want, without stress.
Anyway, I can recommend this design to anyone who wants to build speakers for a SET amp and is constrained by WAF.
You will soon understand why I'm posting about these speakers many years after the event.
The system is pretty good.
Sources:
Teres turntable (acrylic/lead platter), Moerch DP8 arm, Zyx 4D, far better than previous LP12; good valve phono stage.
Marantz CD65 II (TDA1541A dac chip), lots of caps upgrades, NOS converted, lampizated; superb tonality, great sound.
Valve preamp with 27 triode
45 parallel single ended amp, separate PSUs for the two stages, massive PSUs, both 2 pi with chokes, film caps, tuned for fast clean transient response.
Design was constrained by WAF to about 8.5 inches wide, about 12 inches deep and 1 metre high, also by the amp, my 45 parallel SET giving 3.5 watts (note the decimal point). Don't query the amp unless you've heard a 45 SET, if you have you will understand. Room is 18ft x 14ft.
The speaker is about 42 litres, bass reflex to give good sensitivity.
The Q of the bass driver was calculated allowing for amp Zout, giving Qts 0.51 quite high. This made bass alignment a bit of a problem; the ideal volume for a standard alignment became massive. But it was overcome with use of WINisd. With my volume it was not possible to avoid a hump in the bass, but tuning the port to 30Hz got the hump to below 1dB. Group delay was under 10mS at 40Hz (Zaph's criterion), and if I remember, the peak in group delay was moved to quite a low frequency and was not too massive. In fact this is very much Zaph's 'lean and low' tuning; low is obvious, and lean I take to mean removing or minimising the hump at roughly 80 to 100Hz.
Crossover was very similar to Zaph's one for his MTM with Vifa woofers and 27TDFC, virtually as Jay's suggestion; very simple:
Woofers 1.35mH, 40uF
Tweeter 1.9 ohm series R, 12uF, 0.39mH
The L on the woofers adjusted by ear for BSC, starting value 1.4mH was very good.
Tweeter C was adjusted after SPL measurement to reduce a slight dip in the upper crossover region.
The result?
Superb.
Bass is very good, adequate quantity, reasonable depth, very good quality; nothing boomy; tight, tuneful, fast. I had expected to want to try different port lengths, or straws or damping, but once I heard it I told myself, do not mess with anything! (I've messed electronics up in the past and never got back to the best).
Overall, sound is tuneful, fine tonality, good rhythms, excellent leading edges (says a critical friend who loves leading edges and dynamics); superb vocals. Highly musical. Just seems to do lots of things right in a way that you don't notice them, they disappear.
I like the combination of amp and speakers a whole lot, and I'd put it this way.
In hifi, you might have decent hifi sound.
Go a level higher, and it sounds like better hifi, you notice the hifi things more.
But at a higher level still, I find it sounds less like hifi; I don't notice the hifi things, they go away, leaving a very natural presentation.
These speakers are getting close to doing that.
Liked a lot by hifi addict friends; a Naim addict dynamics freak says they have some dynamics and rhythms (and he's critical, blunt with it, like Craig Revel Horwood, for my own good, and he knows his stuff).
The system does not sound underpowered in any way; for one thing the amp sounds more powerful than my 300B SETs of twice the power. Definitely all the volume I want, without stress.
Anyway, I can recommend this design to anyone who wants to build speakers for a SET amp and is constrained by WAF.
You will soon understand why I'm posting about these speakers many years after the event.
The system is pretty good.
Sources:
Teres turntable (acrylic/lead platter), Moerch DP8 arm, Zyx 4D, far better than previous LP12; good valve phono stage.
Marantz CD65 II (TDA1541A dac chip), lots of caps upgrades, NOS converted, lampizated; superb tonality, great sound.
Valve preamp with 27 triode
45 parallel single ended amp, separate PSUs for the two stages, massive PSUs, both 2 pi with chokes, film caps, tuned for fast clean transient response.
Which Markaudio drivers for integrated home streamer?
- By Woody99
- Full Range
- 22 Replies
Hi, first time poster so thanks for all the useful info and expert advice on the forum. I'm building a small cabinet for a stand-alone, wifi/bluetooth home streaming music centre. Movable to any room in the house, compact, easy to use with good quality sound. The cabinet will be approx 600mm W x 200mm H x 300mm D (but can be varied to a limited extent) to house a Fosi MC 101 Class D amp, Wiim Mini streamer (aux out to aux in on the amp) and two small full-range drivers. Each driver will be in enclosed boxes at either end with the amp mounted through the baffle in the middle with Wiim behind, both in a separate central (vented) box. The cabinet ends will be kerfed to create a soft, rounded look which may have some acoustic benefits? Front baffle will be an Australian hardwood called Tasmanian blackwood (19mm) with the case in 15mm veneered ply. Rear ports. A mockup image is below.
I'd like to use Mark Audio drivers for this project and would like to ask which ones you would recommend? The driver units can be 5-7cm and ideally would be gold to match the amp and timber. Volume of each speaker cabinet can be 4-6 litres but I could stretch to 9 litres each by extending height and depth if justified in terms of improvement in sound.
In a prototype I used Dayton Audio PS95-8s in 3.7 litre boxes with a DA KAB amp which sounded good but lacked some bass. I understand bass will be limited in such a small system but am hoping MA drivers would offer some improvement at the low end. This is not a boom box, so it's not just about the bass, I would like to have good mid and upper range too. Most important is to get good, clear sound stage from two drivers close together in near field/small room listening setups for all types of music. Also where on the front baffle would you place the drivers - at the far ends next to the curve or further in towards the middle? Do you see any issues in matching MA drivers with the Fosi (one review on the MA site suggests MA drivers and Class D amps are not a good match)? Any issues achieving the required box volume by departing from the online MA speaker plans by increasing depth and decreasing the other dimensions?
I'd like to use Mark Audio drivers for this project and would like to ask which ones you would recommend? The driver units can be 5-7cm and ideally would be gold to match the amp and timber. Volume of each speaker cabinet can be 4-6 litres but I could stretch to 9 litres each by extending height and depth if justified in terms of improvement in sound.
In a prototype I used Dayton Audio PS95-8s in 3.7 litre boxes with a DA KAB amp which sounded good but lacked some bass. I understand bass will be limited in such a small system but am hoping MA drivers would offer some improvement at the low end. This is not a boom box, so it's not just about the bass, I would like to have good mid and upper range too. Most important is to get good, clear sound stage from two drivers close together in near field/small room listening setups for all types of music. Also where on the front baffle would you place the drivers - at the far ends next to the curve or further in towards the middle? Do you see any issues in matching MA drivers with the Fosi (one review on the MA site suggests MA drivers and Class D amps are not a good match)? Any issues achieving the required box volume by departing from the online MA speaker plans by increasing depth and decreasing the other dimensions?
EAR834p clone with hum. Would appreciate some help
- By AweLoi
- Tubes / Valves
- 159 Replies
Hi everyone!
I have built an EAR 834p clone but have a hum problem. I have followed the grounding scheme (see picture) from the Lenco Heaven forum (and also implemented the mods) but is seems like the amp is picking up noise from the inputs. I am a novice and I am starting to feel that I perhaps took on a project to complicated for me. It is a good sounding phono stage and also some money invested so I would be thankful if someone more knowledgeable would like to help me sort this out so that I can keep this.
I have a Rega P6 turntable with a MC cartridge. I bought it second hand but from a reputable HIFI dealer that had checked it. I have not tested it with anything else than my DIY 834p build. I have not owned a TT since the eighties so I know very little about TT grounding.
After a lot of testing I have been able to pin down a few things regarding the hum. I have built an input switch for MM and MC so that I can easily switch to MM in the future if I like. I have hum even if nothing in connected to either input so I know the hum is from the 834p.
If I switch to MM input, and then ground the switch with a wire, hum is pretty much gone. It disappears completely if I put my hand over the MM inputs (from the back of the amp), I do not even need to touch them, just cover them. Same thing if I hold a piece of metal in front of them. So it seem like the inputs and the switch act like an antenna picking up hum from somewhere. I used an app on my phone and measured the hum. I have a loud 50hz peak, and also a 100hz peak thas is not as loud.
When I plug in my TT to the MM input, there is a faint hum, and it no longer makes any difference if I ground the switch with a wire or not. It's a Rega P6 so it has no separate ground cable. Ground in Rega TTs is in the left channel cable. Don't know if that has anything to do with it.
If I switch to MC, with nothing connected to the input, which goes from inputs trough a pair of Lundahl LL1931 SUTs and the to the switch, I still have hum even with the switch grounded. A tiny bit little less when grounded, but not much. I have tried different grounding schemes for the Lundahls and this is the most quiet one, but still way too loud. I only have a MC cartridge, so if I want to listen to vinyl, hum will be present if I do not solve this.
In my build I have made it so that the switch switches both + and -. Is that a bad idea?
I have changed all the unshielded input wires on the picture to shielded, no difference.
Also there is a problem with hum with the Rega P6. I get a really loud hum when I touch the tonearm and sometimes it stays after I let go of it, sometimes not. If I move around the input cables from the Rega this loud hum can also start. When I get this hum, I can cancel it by putting a wire from Right input - (shield) to amp chassis (not the Left channel that supposedly has the TT ground), but if I leave this wire permanently in place I still get hum if I touch the tonearm and to cancel the hum I now need to remove the wire.
All of this is so weird to me.
So, what can I do now as the next step? Do I need to ground my inputs in another manner perhaps? I have seen that some people connect all input - to each other and some don't. I am at loss at this point.
I have built an EAR 834p clone but have a hum problem. I have followed the grounding scheme (see picture) from the Lenco Heaven forum (and also implemented the mods) but is seems like the amp is picking up noise from the inputs. I am a novice and I am starting to feel that I perhaps took on a project to complicated for me. It is a good sounding phono stage and also some money invested so I would be thankful if someone more knowledgeable would like to help me sort this out so that I can keep this.
I have a Rega P6 turntable with a MC cartridge. I bought it second hand but from a reputable HIFI dealer that had checked it. I have not tested it with anything else than my DIY 834p build. I have not owned a TT since the eighties so I know very little about TT grounding.
After a lot of testing I have been able to pin down a few things regarding the hum. I have built an input switch for MM and MC so that I can easily switch to MM in the future if I like. I have hum even if nothing in connected to either input so I know the hum is from the 834p.
If I switch to MM input, and then ground the switch with a wire, hum is pretty much gone. It disappears completely if I put my hand over the MM inputs (from the back of the amp), I do not even need to touch them, just cover them. Same thing if I hold a piece of metal in front of them. So it seem like the inputs and the switch act like an antenna picking up hum from somewhere. I used an app on my phone and measured the hum. I have a loud 50hz peak, and also a 100hz peak thas is not as loud.
When I plug in my TT to the MM input, there is a faint hum, and it no longer makes any difference if I ground the switch with a wire or not. It's a Rega P6 so it has no separate ground cable. Ground in Rega TTs is in the left channel cable. Don't know if that has anything to do with it.
If I switch to MC, with nothing connected to the input, which goes from inputs trough a pair of Lundahl LL1931 SUTs and the to the switch, I still have hum even with the switch grounded. A tiny bit little less when grounded, but not much. I have tried different grounding schemes for the Lundahls and this is the most quiet one, but still way too loud. I only have a MC cartridge, so if I want to listen to vinyl, hum will be present if I do not solve this.
In my build I have made it so that the switch switches both + and -. Is that a bad idea?
I have changed all the unshielded input wires on the picture to shielded, no difference.
Also there is a problem with hum with the Rega P6. I get a really loud hum when I touch the tonearm and sometimes it stays after I let go of it, sometimes not. If I move around the input cables from the Rega this loud hum can also start. When I get this hum, I can cancel it by putting a wire from Right input - (shield) to amp chassis (not the Left channel that supposedly has the TT ground), but if I leave this wire permanently in place I still get hum if I touch the tonearm and to cancel the hum I now need to remove the wire.
All of this is so weird to me.
So, what can I do now as the next step? Do I need to ground my inputs in another manner perhaps? I have seen that some people connect all input - to each other and some don't. I am at loss at this point.
Speaker gasket sealing tape
Hello,
I can access places like Element14 (Newark USA, and known as Farnell in UK) or Digikey.
The tweeter as you can see has a fine tape - more to maybe hold the copper dome down. The woofer the foam has long gone, or never was used. The speakers are Celestion SL-6. I fixed the corrosion issue in another thread back in December, with Rust Oleumn 5in1 paint
https://au.element14.com/pro-power/hsht-roll-0-8x25mmx5m/tape-pe-foam-5m-x-25mm/dp/7224825
tweeter and maybe woofer
for the woofer maybe
https://au.element14.com/multicomp-pro/ppc116/sealing-tape-pvc-25m-x-6mm/dp/176068601
I can access places like Element14 (Newark USA, and known as Farnell in UK) or Digikey.
The tweeter as you can see has a fine tape - more to maybe hold the copper dome down. The woofer the foam has long gone, or never was used. The speakers are Celestion SL-6. I fixed the corrosion issue in another thread back in December, with Rust Oleumn 5in1 paint
https://au.element14.com/pro-power/hsht-roll-0-8x25mmx5m/tape-pe-foam-5m-x-25mm/dp/7224825
tweeter and maybe woofer
for the woofer maybe
https://au.element14.com/multicomp-pro/ppc116/sealing-tape-pvc-25m-x-6mm/dp/176068601
HV B+ linear shunt regulator ringing
- By SomeJoe
- Power Supplies
- 1 Replies
Hello,
I am testing a design of mine for tube amp B+ supplies, both for input and output stages. Currently setup for the lower current input stage, running at the top of its adjustable range, 170V/75mA, with the shunt mosfet (IRF820) run in linear region (of course) dumping 40mA current. This is a stress test to check for thermal stability and worst-case scenario performance - the shunt will dump a bit less power in normal operation (25-30 mA at 150V). Looks that will make for a decent space heater if anything 😎
I am satisfied with line regulation (about 150mV pk-pk), but there is a great deal of ringing (see scope shots). First one is blurred but only there to show the main ripple voltage with the ringing around it as light green, next two pics are close-ups. Sorry with the bad shots, I have only an old scope and I'm not that good working with it. I have measured around 100mV pk-pk ringing at about 50 KHz. Is that to be expected? Note that these preliminary tests were done into a 5K dummy load, without "speed-up" capacitor C1 and output capacitor C3.
50mV/div, 0.50mS/div
20mV/div, 50uS/div
20mV/div, 20uS/div
A few more circuit details: The top device M1 is an IXYS IXCP10M45S current source; The shunt mosfet M3 has a 100 ohm stopper resistor soldered close to the gate (see board pic below). It is a dual mono board with all TO-220 devices on the same heatsink with ceramic insulating pads. In the actual builds the heatsinks will be mechanically connected to the grounded metallic chassis. This test setup doesn't use the heatsink that will be used in actual project but uses the actual adapter bracket (the aluminium flat bar the tabs screw into) and heatsinks are left floating. I will check with grounded heatsinks tomorrow.
I have measured a substantial capacitance of 50-100 nF between the TO-220 tabs (drains) and the heatsink - That can't be good, I fear HF coupling between devices and channels... I have tested only a channel at a time so far. I am not very experienced with parasitics management and would appreciate any advice on how to tame the ringing. I have often seen ferrite beads used in SPMS designs, presumably on the gate lead. Can it help here?
Thanks in advance.
- Joris
I am testing a design of mine for tube amp B+ supplies, both for input and output stages. Currently setup for the lower current input stage, running at the top of its adjustable range, 170V/75mA, with the shunt mosfet (IRF820) run in linear region (of course) dumping 40mA current. This is a stress test to check for thermal stability and worst-case scenario performance - the shunt will dump a bit less power in normal operation (25-30 mA at 150V). Looks that will make for a decent space heater if anything 😎
I am satisfied with line regulation (about 150mV pk-pk), but there is a great deal of ringing (see scope shots). First one is blurred but only there to show the main ripple voltage with the ringing around it as light green, next two pics are close-ups. Sorry with the bad shots, I have only an old scope and I'm not that good working with it. I have measured around 100mV pk-pk ringing at about 50 KHz. Is that to be expected? Note that these preliminary tests were done into a 5K dummy load, without "speed-up" capacitor C1 and output capacitor C3.
50mV/div, 0.50mS/div
20mV/div, 50uS/div
20mV/div, 20uS/div
A few more circuit details: The top device M1 is an IXYS IXCP10M45S current source; The shunt mosfet M3 has a 100 ohm stopper resistor soldered close to the gate (see board pic below). It is a dual mono board with all TO-220 devices on the same heatsink with ceramic insulating pads. In the actual builds the heatsinks will be mechanically connected to the grounded metallic chassis. This test setup doesn't use the heatsink that will be used in actual project but uses the actual adapter bracket (the aluminium flat bar the tabs screw into) and heatsinks are left floating. I will check with grounded heatsinks tomorrow.
I have measured a substantial capacitance of 50-100 nF between the TO-220 tabs (drains) and the heatsink - That can't be good, I fear HF coupling between devices and channels... I have tested only a channel at a time so far. I am not very experienced with parasitics management and would appreciate any advice on how to tame the ringing. I have often seen ferrite beads used in SPMS designs, presumably on the gate lead. Can it help here?
Thanks in advance.
- Joris
For Sale I have 10 brand-new LM3886-based composite amp boards for sale cheap
I just built 20 high quality composite chipamp (class AB) amplifier boards but only really need 10 and would like to sell the extras. These are my version 5 (sigh) but they're finally pretty good and what with high fixed-costs I decided to build more than I need.
Contents: completed and tested amplifier board(s)
Not included: power supply ; heatsinks; case
Price: $50 each (minimum of two). Free shipping CONUS.
Options: with a small ballast resistor they can run in parallel or bridged for higher power or lower impedance or better heat dissipation
SPECS: balanced inputs, up to about 40WRMS@8 or 60WRMS@4 ohms depending on power supply. At higher power the distortion specs don't change much other than better S/N.
POWER REQUIREMENTS: +-22 up to +-40V. Higher voltages are 8 ohm only unless paralleled amps. The amp voltage swing is a bit less than the power supply. The measurements are remarkably consistent between samples and very good but not guaranteed identical. Higher voltages generate a lot more heat. At +-25VDC it's a 40W@4 amp.
Here's the first sample's 5W@4 ohms. Here I'm powering it with 2 bridged Meanwell LRS-150-24 power supplies @25VDC. A linear supply would be slightly quieter. This was unbalanced input and the output choke hasn't been glued together yet 🙂 ->
I'll add more detail if requested. Warranty: it's tough to warranty something you can destroy by powering backwards or ... but I guarantee I will test/validate them before ship and include a printout of 5W@4 result for the board itself that should look much like this.
I've attached the REW file with my first tests. Note that the dynamic range of the amps is more than my test equipment so I have to test higher powers (>5 Watts) with a voltage divider which adds noise. I mark those as -6 or -10 (6db or 10db dividers).
My personal opinion is that these sound better than any amplifier I've ever owned. I listen to music at moderate sound levels on fairly efficient speakers. I use 4 of these amplifiers per channel (two in parallel for 4ohm woofer, one mid, one tweeter) in a DSP amplifier setup (so 8 total for stereo) - hence the need for 10.
Mark
Contents: completed and tested amplifier board(s)
Not included: power supply ; heatsinks; case
Price: $50 each (minimum of two). Free shipping CONUS.
Options: with a small ballast resistor they can run in parallel or bridged for higher power or lower impedance or better heat dissipation
SPECS: balanced inputs, up to about 40WRMS@8 or 60WRMS@4 ohms depending on power supply. At higher power the distortion specs don't change much other than better S/N.
POWER REQUIREMENTS: +-22 up to +-40V. Higher voltages are 8 ohm only unless paralleled amps. The amp voltage swing is a bit less than the power supply. The measurements are remarkably consistent between samples and very good but not guaranteed identical. Higher voltages generate a lot more heat. At +-25VDC it's a 40W@4 amp.
Here's the first sample's 5W@4 ohms. Here I'm powering it with 2 bridged Meanwell LRS-150-24 power supplies @25VDC. A linear supply would be slightly quieter. This was unbalanced input and the output choke hasn't been glued together yet 🙂 ->
I'll add more detail if requested. Warranty: it's tough to warranty something you can destroy by powering backwards or ... but I guarantee I will test/validate them before ship and include a printout of 5W@4 result for the board itself that should look much like this.
I've attached the REW file with my first tests. Note that the dynamic range of the amps is more than my test equipment so I have to test higher powers (>5 Watts) with a voltage divider which adds noise. I mark those as -6 or -10 (6db or 10db dividers).
My personal opinion is that these sound better than any amplifier I've ever owned. I listen to music at moderate sound levels on fairly efficient speakers. I use 4 of these amplifiers per channel (two in parallel for 4ohm woofer, one mid, one tweeter) in a DSP amplifier setup (so 8 total for stereo) - hence the need for 10.
Mark
"There and back" by Ken Fritz
- The Lounge
- 64 Replies
threee threads on Ken Fritz merged, 
diyAudio moderation team
A remarkable DIY audiophile journey by a remarkable man, Ken Fritz Login to view embedded media
diyAudio moderation teamA remarkable DIY audiophile journey by a remarkable man, Ken Fritz Login to view embedded media
CHP-90 bookshelf design question
- By sdsddsd1
- Full Range
- 2 Replies
I want to build something new. After some sucessful builds of planet10´s CGR for CHP-70 and Woden Design´s for CHN-50 I want to build something with a bigger driver but still for a smallish place, aproximately 20sqm.
I am quite fond of the looks from the classic golden ratios. The CGR for CHP-70 shall be the model dimension/ratio wise.
http://frugal-phile.com/boxlib/P10free/CGR-dKal-El703-301113.pdf
My idea is to take the general alignment from the "compact vented" one from the Markaudio site. I think its from Scott and fit a slot port on the side.
https://www.markaudio.com/wp-content/uploads/2022/05/CHP90-compact-vented.png
F6=46Hz and FB=46Hz according to plans.
The Volume is Vbox=12,47l and the 40mm round port is A=12,57cm l=12,3cm. I put the data into hornresp and got a frequency graph like this.
F6 is roughly 48Hz and FB 42,1Hz. I have double checked my data but this is what I got in HR.
My slot port should be 14cm wide and 15mm high. To reach the same FB=42,1 it has to be l=20,8cm. This is with a Vbox=13,11l. I had to increase the volume slightly because I upsacaled the CGR ratio by 15% and I want to stay on even numbers. The graphs are not the same but very similar from my point of view.
This is my first time designing a box. There might be stuff I missed or just dont know 🙂
Now my masterquestion. Can I do the box like this? Should this work or is this too far off from the original design?
I know, when using a slot port its adding R to the vent and pushing it more towards aperiodic while decreasing port output.
I attached my hornresp records in case somebody wants to have a look.
What comes to mind that I might change the port ouput which might had helped to fill baffle step losses? Also by placing the driver off centre. But this is just a guess which I can just assume.
I am quite fond of the looks from the classic golden ratios. The CGR for CHP-70 shall be the model dimension/ratio wise.
http://frugal-phile.com/boxlib/P10free/CGR-dKal-El703-301113.pdf
My idea is to take the general alignment from the "compact vented" one from the Markaudio site. I think its from Scott and fit a slot port on the side.
https://www.markaudio.com/wp-content/uploads/2022/05/CHP90-compact-vented.png
F6=46Hz and FB=46Hz according to plans.
The Volume is Vbox=12,47l and the 40mm round port is A=12,57cm l=12,3cm. I put the data into hornresp and got a frequency graph like this.
F6 is roughly 48Hz and FB 42,1Hz. I have double checked my data but this is what I got in HR.
My slot port should be 14cm wide and 15mm high. To reach the same FB=42,1 it has to be l=20,8cm. This is with a Vbox=13,11l. I had to increase the volume slightly because I upsacaled the CGR ratio by 15% and I want to stay on even numbers. The graphs are not the same but very similar from my point of view.
This is my first time designing a box. There might be stuff I missed or just dont know 🙂
Now my masterquestion. Can I do the box like this? Should this work or is this too far off from the original design?
I know, when using a slot port its adding R to the vent and pushing it more towards aperiodic while decreasing port output.
I attached my hornresp records in case somebody wants to have a look.
What comes to mind that I might change the port ouput which might had helped to fill baffle step losses? Also by placing the driver off centre. But this is just a guess which I can just assume.
RCA sound system needing to utilize Bluetooth
- By Chris516
- Equipment & Tools
- 0 Replies
Here is the link to thread I started back in Dec.'2023 in the Windows 11 Forum: https://forums.tomshardware.com/threads/no-audio-output.3831037/
The pic above is the Logitech Z-2200 2.1 speaker system that I bought in 2004. In 2007, I moved, and had to leave the bass, but kept the satellites.
In 2008, I bought Logitech's Z-2300 2.1 speaker system.
Which now made it a 4.1 system. Sound was fine, until the audio output driver somehow went bad(PC is from Best Buy in 2019). I tried to re-install the driver, multiple times. But with no success. The speakers are RCA connection.
I had a local PC tech come by over the weekend. He came to the conclusion I was dreading. He said I would have to start using the Bluetooth capability. So, I am trying to figure out. How to enable using the Bluetooth capability on my PC. While still being able to use my external speakers.
RSVP ASAP TIA
Meet GSL - Gunillas Song Box
- By TNT
- PA Systems
- 2 Replies
(swe: Låda (box))
I found my sister Gunilla singing via a floor standing guitar amp at rehearsals etc… not ideal. I offered to build her a transportable PA for song and she accepted.
So it needed to be based on a sack carrier and a small lightweight loudspeaker. Me wanted to give it some proper performance in terms of fidelity as well as good wide coverage. Concerts are given but typically to smaller crowds - say a max of 50 persons in a couple of 100 sqm. Very simple operation is desired.
I came up with this concept sketch:
Its based on:
XO: 2,3kHz, 4th.
BOM: 750€ / 30 hours.
Dimensions:
It can be configured to play 5 different positions:
All electronics are mounted to a separating wall in the carrying box which in turn is mounted to the sack carrier. Loudspeaker is completely passive - spiral cord between amp and loudspeaker has 3 leads.
Operation entails:
It’s very near completion - I’m waiting for a new selector for the “Mode” switch as I got a BBM but a MBB was required.
Next up is meeting up with the artist to do sound check and personalised tuning. But before that some standard measurement here at home. Home is a small, one room, flat which has made the build not so easy - a very small kitchen is not an ultimate workshop ;-D
//
I found my sister Gunilla singing via a floor standing guitar amp at rehearsals etc… not ideal. I offered to build her a transportable PA for song and she accepted.
So it needed to be based on a sack carrier and a small lightweight loudspeaker. Me wanted to give it some proper performance in terms of fidelity as well as good wide coverage. Concerts are given but typically to smaller crowds - say a max of 50 persons in a couple of 100 sqm. Very simple operation is desired.
I came up with this concept sketch:
Its based on:
- Sica 10” (10 C 2 CP 8Ω) bass prepared for coaxial tweeter
- Lavoce 1” CD (DF10.10L-8)
- Mic amplifier 2-channel but used as balanced
- t.track DSP 4x4 pro for XO, EQ and compression/gate
- 2x80W class-D TI based amp
XO: 2,3kHz, 4th.
BOM: 750€ / 30 hours.
Dimensions:
It can be configured to play 5 different positions:
- staying in transport box for quick sessions… (not ideal but usable)
- sitting on top of transport box
- mounted on sack carrier handle - handle in low position
- mounted on sack carrier handle - handle in extended position
- sitting on table etc. within 3m from transport box which is max extension for the spiral cord used
All electronics are mounted to a separating wall in the carrying box which in turn is mounted to the sack carrier. Loudspeaker is completely passive - spiral cord between amp and loudspeaker has 3 leads.
Operation entails:
- Take out power cable(s)
- Lift out speaker
- Connect to mains
- Adjust volume
- Choose “mode” - three different (EQ, compression) settings for different sound characteristics - thats it.
- Nock-em’out with some pop-jazz….
- Write autographs
It’s very near completion - I’m waiting for a new selector for the “Mode” switch as I got a BBM but a MBB was required.
Next up is meeting up with the artist to do sound check and personalised tuning. But before that some standard measurement here at home. Home is a small, one room, flat which has made the build not so easy - a very small kitchen is not an ultimate workshop ;-D
//
Attachments
Quick question on speakers grounding with bleeder resistor
- By Michelag
- Analog Line Level
- 1 Replies
Attachments
Amp enclosure
- By Kyleag89
- Construction Tips
- 9 Replies
I'm going to be ordering a class d amp board from Aiyima to power a passive subwoofer I have. How would you guys go about putting this in an enclosure? I've built and bought diy enclosures before for small class d modules, but not for an amp where heat can be a big issue. I'm looking for ideas and/or tips on putting something like this board into an enclosure. Thanks
Damo Suzuki RIP
- By stonegreen
- Music
- 0 Replies
Kenji Suzuki (鈴木健次, Suzuki Kenji, 16 January 1950 – 9 February 2024), known as Damo Suzuki
Vocalist of the German Krautrock group Can
The band “Can” on December 1st, 1971 in Hamburg. (L-R): Irmin Schmidt, Jaki Liebezeit, Michael Karoli, Ulli Gerlach, Holger Szukay and in front Damo Suzuki. (dpa)
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Vocalist of the German Krautrock group Can
The band “Can” on December 1st, 1971 in Hamburg. (L-R): Irmin Schmidt, Jaki Liebezeit, Michael Karoli, Ulli Gerlach, Holger Szukay and in front Damo Suzuki. (dpa)
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Chip amp + MOSFET composite
- Chip Amps
- 29 Replies
Why to enhance a chip amp?
The trouble with these amps they are designed as opamps for stability and easy for use. The downside is very low NFB at high frequencies. In modern amps with two pole OLG, one can get over 50db NFB@20khz, while chip amps hardly reaches 30db. This results in low resolution amplifier with bad reproduction of complex vocals or large orchestras.
A simple way to correct, is to add a MOSFET to pump extra gain at OLG. The chip amp is used as its highest possible IV converting gain and the MOSFET converts the error voltage into current.
The universal circuit is shown bellow using LM3886 as simulation model compared to its application circuit. The Loop gain curves show how the initial 25db NFB@20khz leaps to 60db with MOSFET. The distortion is not implemented but the noise is. Comparing the output noise at 1khz, the 41.7uv of the initial circuit gets reduced to 0.7uv with MOSFET, this is 58 times lower which I estimate the distortion of the chip alone gets also reduced by the same factor.
I tried this circuit on Chinese TDA2050-LM1875, TDA7294 and LM3886. The best sounding I got is with 7294. Besides getting very smooth high frequencies, it has a wide, generous midrange that reminds me 45rpm records. With 3886, every time I tried this chip in composit, the voices goes back stage, with MOSFET, I got the worst ever of such type of sound. If I don't like it, many consider it better as they call it 3D sound or holographic.
The 7293 has 0.005%THD 1khz 5W, it gets reduced to 0.0001% to add the THD of 2N7000 of 0.0005% it should result less than 0.0006% in total.
The power supply will be a semi floating type for better bass using conventional psu, with SMPS, the positive input of the chip needs to be referenced to a virtual ground(2x10k resistors from rails).
I will design a PCB for 7293.
The trouble with these amps they are designed as opamps for stability and easy for use. The downside is very low NFB at high frequencies. In modern amps with two pole OLG, one can get over 50db NFB@20khz, while chip amps hardly reaches 30db. This results in low resolution amplifier with bad reproduction of complex vocals or large orchestras.
A simple way to correct, is to add a MOSFET to pump extra gain at OLG. The chip amp is used as its highest possible IV converting gain and the MOSFET converts the error voltage into current.
The universal circuit is shown bellow using LM3886 as simulation model compared to its application circuit. The Loop gain curves show how the initial 25db NFB@20khz leaps to 60db with MOSFET. The distortion is not implemented but the noise is. Comparing the output noise at 1khz, the 41.7uv of the initial circuit gets reduced to 0.7uv with MOSFET, this is 58 times lower which I estimate the distortion of the chip alone gets also reduced by the same factor.
I tried this circuit on Chinese TDA2050-LM1875, TDA7294 and LM3886. The best sounding I got is with 7294. Besides getting very smooth high frequencies, it has a wide, generous midrange that reminds me 45rpm records. With 3886, every time I tried this chip in composit, the voices goes back stage, with MOSFET, I got the worst ever of such type of sound. If I don't like it, many consider it better as they call it 3D sound or holographic.
The 7293 has 0.005%THD 1khz 5W, it gets reduced to 0.0001% to add the THD of 2N7000 of 0.0005% it should result less than 0.0006% in total.
The power supply will be a semi floating type for better bass using conventional psu, with SMPS, the positive input of the chip needs to be referenced to a virtual ground(2x10k resistors from rails).
I will design a PCB for 7293.
JFET with matched JFET current sink for linearising
- By Booberg
- Electronic Design
- 35 Replies
I came up with this basic configuration while digging into ways of emulating triode like behaviour with depletion FETs. Maybe broaching this topic is like beating a dead horse and no one wants to hear about it at this point, but I found it a bit curious that I have never come across this method.
Bare bones scetch:
Simulation in Falstad (perhaps questionable in accuracy from what i know about falstads transistor simulations):
(Left plot is the input waveform and right plot is the output.)
To give a bit of context. What I am really after is nice saturation characteristics in amplification stages that can be affected by power sag. I read (I forget where) that one major drawback of resistive NFB, as a method for achieving triode like transfer characteristics, is that triode tubes display something roughly equivalent to nonlinear internal NFB. And people usually emulate this by the use of diodes. My hypothesis is that using a matched JFET as a current drain in this configuration can open up the possibility to really dial in the NFB and make the transfer characteristics as linnear and symmetrical as you would like.
This is in itself not very different from using the well known "solid state cascode" configuration, but I primarily found that this was way easier to get biased properly in simulation. As you can see I only used one drain resistor and "cathode bypass" with nice results. (To retain more asymmetry, a resistor can be placed in parallel with the bottom JFET). Aditionally, it should work as I intend by using matched (or dual) transistors, while I have read that cascodes often require "complementary" transistors to work properly (??).
Would love to hear what you all have to say about the general idea, possible drawbacks or complications etc. Have you seen it before? Does it have a name?
My next step will be to implement it in LTSpice to hopefully verify the performance with a bit more reliability, take more "proper" meassurements, and examine how it behaves under different loads.
PS. This is my first post after years of spying on many great conversations. I'm very impressed by this community's knowleadability and generally friendly demeanour. Please be kind if I break any rules or some such, it's just lack of knowledge 😀
Cheers!
Bare bones scetch:
Simulation in Falstad (perhaps questionable in accuracy from what i know about falstads transistor simulations):
(Left plot is the input waveform and right plot is the output.)
To give a bit of context. What I am really after is nice saturation characteristics in amplification stages that can be affected by power sag. I read (I forget where) that one major drawback of resistive NFB, as a method for achieving triode like transfer characteristics, is that triode tubes display something roughly equivalent to nonlinear internal NFB. And people usually emulate this by the use of diodes. My hypothesis is that using a matched JFET as a current drain in this configuration can open up the possibility to really dial in the NFB and make the transfer characteristics as linnear and symmetrical as you would like.
This is in itself not very different from using the well known "solid state cascode" configuration, but I primarily found that this was way easier to get biased properly in simulation. As you can see I only used one drain resistor and "cathode bypass" with nice results. (To retain more asymmetry, a resistor can be placed in parallel with the bottom JFET). Aditionally, it should work as I intend by using matched (or dual) transistors, while I have read that cascodes often require "complementary" transistors to work properly (??).
Would love to hear what you all have to say about the general idea, possible drawbacks or complications etc. Have you seen it before? Does it have a name?
My next step will be to implement it in LTSpice to hopefully verify the performance with a bit more reliability, take more "proper" meassurements, and examine how it behaves under different loads.
PS. This is my first post after years of spying on many great conversations. I'm very impressed by this community's knowleadability and generally friendly demeanour. Please be kind if I break any rules or some such, it's just lack of knowledge 😀
Cheers!
Crossover analysis and baffle diffraction
I found two loudspeakers that are three-way configuration have the same drivers except woofers and enclosures: ADS L980/2 and L1590/2. Despite the same mids and tweeters, their crossovers on mids and tweeters are different.
However, there exists similar situation in the previous series: ADS L810 and L1230. The L810 and L1230 have exactly the same ALL drivers and crossovers, and only EXCEPT the cabinets.
Back to the L980/2 and L1590/2, the crossovers are simply second-order on both high-pass and low-pass section.
The component values are different as follows:
L980/2: C1 = 4.7uF, L1 = 0.3mH, C2 = 13.6uF, L2 = 0.6mH
L1590/2: C1 = 6.8uF, L1 = 0.2mH, C2 = 15uF, L2 = 0.4mH
I’ve already put these values into simulation software, VituixCAD2, to see their filter’s characteristics. It showed the L1590/2 has peaky SPL response at the crossover region, whereas the L980/2 has smaller peak there.
I wonder why they were designed different mid-to-high crossovers, unlike the other case mentioned above—L810 and L1230. Is it because the baffle diffraction theory? AFAIK, the baffle diffraction would affect in the low frequency region, i.e., the woofer and cabinet interaction. So, they might be able to use the same crossovers (for mid-to-high), weren’t they?
PS. JBL L112 and L96 also use the same crossovers despite the different components including drivers, cabinet dimension and baffle size.
However, there exists similar situation in the previous series: ADS L810 and L1230. The L810 and L1230 have exactly the same ALL drivers and crossovers, and only EXCEPT the cabinets.
Back to the L980/2 and L1590/2, the crossovers are simply second-order on both high-pass and low-pass section.
The component values are different as follows:
L980/2: C1 = 4.7uF, L1 = 0.3mH, C2 = 13.6uF, L2 = 0.6mH
L1590/2: C1 = 6.8uF, L1 = 0.2mH, C2 = 15uF, L2 = 0.4mH
I’ve already put these values into simulation software, VituixCAD2, to see their filter’s characteristics. It showed the L1590/2 has peaky SPL response at the crossover region, whereas the L980/2 has smaller peak there.
I wonder why they were designed different mid-to-high crossovers, unlike the other case mentioned above—L810 and L1230. Is it because the baffle diffraction theory? AFAIK, the baffle diffraction would affect in the low frequency region, i.e., the woofer and cabinet interaction. So, they might be able to use the same crossovers (for mid-to-high), weren’t they?
PS. JBL L112 and L96 also use the same crossovers despite the different components including drivers, cabinet dimension and baffle size.
Pairing SMPS with a CRC filter
- By vagabond1981
- Power Supplies
- 7 Replies
Hi There,
I've purchased a Nelson Pass F4 amp kit and just recieved it.
I went ahead and purchased 2 X 24V+- 350w SMPS units online. my question is, can i filter the SMPS DC output using a CRC power filter board like the one below (bypass the AC to DC conversion). and is it worth it?
Also, I've read somewhere that CRC filter configuration is supirior than just using filter capacitors, can someone help me understand why.
Thanks in advance. 🙂
I've purchased a Nelson Pass F4 amp kit and just recieved it.
I went ahead and purchased 2 X 24V+- 350w SMPS units online. my question is, can i filter the SMPS DC output using a CRC power filter board like the one below (bypass the AC to DC conversion). and is it worth it?
Also, I've read somewhere that CRC filter configuration is supirior than just using filter capacitors, can someone help me understand why.
Thanks in advance. 🙂
Community Blender Horns
Below is a ball that I've got rolling but I hope to involve others. I desire to design basic Waveguides/Horns but I want to do so in a Wysiwyg fashion. So far, just from starting a thread on the blender forums, I see the potential for something easy, free and accessible to the community. The Geometry Node section of Blender is modulistic, in a good way. It also has a learning curve. I think with the superpower of community effort, we could cover ground pretty quickly. Lets share ideas and developments here and use the Blender Forum thread, linked in the pictures, to work with the Blender Wizards there to further our efforts. This has been a goal of mine, and as I make progress I will share it here. I know with community involvement it will be much better and quicker developing, its just a matter of, the community taking interest. So far I can create the shapes of various Round, Elliptical, Square/Rectangle, and soon Squircle mouthed waveguides, with expansion profiles that can be designed visually. The goal would be to develop a Geometry Node set up, to the point of producing simple printable models within a short amount of time. Anything that I have is downloadable in the thread linked. Good Luck 😉
Decware Zkit4 potentiometer placement
- Analog Line Level
- 4 Replies
Where would a pot be placed in this circuit to control the gain. I have read in various places that a 100k pot can be used on the output side. Would it just replace the 100k resistor or be added in addition to the existing 100k resistor on the output? Or somewhere else?
