Tnx Andrew for the repply
Im only considering on driving a ribbon actively from 1KHz up, and since the impedance at that Frequency is higher and also lower power at that Frequency range, could it work as a good solution or could we use even the jlh1969 with a lower CAP. value for this purpose . Ive only heard the 1969 version and love the sound of it.
Regards
João
Im only considering on driving a ribbon actively from 1KHz up, and since the impedance at that Frequency is higher and also lower power at that Frequency range, could it work as a good solution or could we use even the jlh1969 with a lower CAP. value for this purpose . Ive only heard the 1969 version and love the sound of it.
Regards
João
Ribbons don't have much inductance.
Their impedance is fairly flat over their operating range.
If it's 4ohms (pretty near 4r) at 1kHz, it's likely to be pretty close to 4r at 20kHz.
12Vpk into 4r is 3Apk (9W into 8r0). But your amp should be designed to pass much more transient current. Into this single driver I would aim for twice as much i.e. around 6Apk.
That is beyond a normally biased JLH
Their impedance is fairly flat over their operating range.
If it's 4ohms (pretty near 4r) at 1kHz, it's likely to be pretty close to 4r at 20kHz.
12Vpk into 4r is 3Apk (9W into 8r0). But your amp should be designed to pass much more transient current. Into this single driver I would aim for twice as much i.e. around 6Apk.
That is beyond a normally biased JLH
Hi Siliconray and everybody!
Can you, or anybody else in fact, tell me what is the size of PCB-s for amp and for PSU?
Also, got some thinking about RE2109H enclosure for monoblock variant.
Does anyone got anny comment about that enclosure for mono variant of JLH 2005? How much current/heat you think they can handle?
http://www.siliconray.com/re2109-211x90x257-aluminum-enclosure.html
That's why I asking for PCB size.
EDITED: Previous link leaded to wrong chassis.
Can you, or anybody else in fact, tell me what is the size of PCB-s for amp and for PSU?
Also, got some thinking about RE2109H enclosure for monoblock variant.
Does anyone got anny comment about that enclosure for mono variant of JLH 2005? How much current/heat you think they can handle?
http://www.siliconray.com/re2109-211x90x257-aluminum-enclosure.html
That's why I asking for PCB size.
EDITED: Previous link leaded to wrong chassis.
Last edited:
Hi
Amp.PCB:104*71,mount.holes:97*64
PSU ?
About RE2109H,dont now about the C/W*,but a monoblock with the power-transistors mounted one on each side (fin) it will be a nice handwarm enclosure.
These chinese enclosures are really good,hi prof. manufactured,some may find the look a bit rough.
I got 3 now.
RE3213H for the ACA (stereo)
JC2212 for the 2005 w/externel heatsinks (stereo)
RE2109H for the JC-2 preamp and remote ctrl.
Jan
Amp.PCB:104*71,mount.holes:97*64
PSU ?
About RE2109H,dont now about the C/W*,but a monoblock with the power-transistors mounted one on each side (fin) it will be a nice handwarm enclosure.
These chinese enclosures are really good,hi prof. manufactured,some may find the look a bit rough.
I got 3 now.
RE3213H for the ACA (stereo)
JC2212 for the 2005 w/externel heatsinks (stereo)
RE2109H for the JC-2 preamp and remote ctrl.
Jan
Thank you Speedless!
So it would be about 5 or so cm of wire between PCB and output transistors. Guess that is fine.
If I understand part of your sentence "it will be a nice handwarm enclosure" correctly - you actually said: "Go for it! It will be warm enough to lay your hand on it without worry"? Or did I missinterpret it?
In either way thank you for reply!
Regards, Mladen
So it would be about 5 or so cm of wire between PCB and output transistors. Guess that is fine.
If I understand part of your sentence "it will be a nice handwarm enclosure" correctly - you actually said: "Go for it! It will be warm enough to lay your hand on it without worry"? Or did I missinterpret it?
In either way thank you for reply!
Regards, Mladen
Hi
Mladen
Yes go for it for a monoblock.
I missed out the "ing" in handwarming.
You will need Alu-L profiles for mounting the power transistors.
PSU;Trafo:18-0-18v/80-100VA,retifier:5-A,caps:min.4700Uf.Each channel
Get the cap-multifier board also.Free Power Supply PCB For JLH Amplifier - Boards | Kits | Components | Modules | Tools
Jan
Mladen
Yes go for it for a monoblock.
I missed out the "ing" in handwarming.
You will need Alu-L profiles for mounting the power transistors.
PSU;Trafo:18-0-18v/80-100VA,retifier:5-A,caps:min.4700Uf.Each channel
Get the cap-multifier board also.Free Power Supply PCB For JLH Amplifier - Boards | Kits | Components | Modules | Tools
Jan
Attachments
Speedless, my english is not native. So didn't even think you got misspeled it.
Hopefully, will make an capacitance multiplier on proto boards as Geoff published it on his site.
The Class-A Amplifier Site - Updated Power Supply
So far I have located most parts for project. Will not buy kit, but the chassis is challenge for me to fabricate.
One thing puzzles me anyway, if I use cap multiplier as provided on link above what will be the voltage drop across cap multiplier?
I am aware with classical CRC or CLC PSU the output voltage will be Usec x 1,41 (without losses. In realitty more like Usec x 1,3 or so). But here we got only C and after that some cap "amplifier" with voltage reg. How much voltage will I need on transformer secundars to achieve stabile 22V after multiplier and regulation?
Was searching threads for couple of days now without succsess.
(As you can see, i'm no electronic master.)
I promise I will bother you no more after this.
Hi
Im using a 18-0-18 V/180 V/A trafo:for both channels,10 A rectifier,2*10000uF caps and a cap-multiplier for each channel.Vout:ca.24V
Why exactly 22V ? Works fine with 24V.
Trafo for the regulater board (Updated Power Supply) :min.24-0-24V/min.100V/A.
The regulator and the cap-multiplier will both need cooling,not sure if the finns on this enclosure can handle it with the pwr.trans.
Introducing more;heat,potentially noice from IC's,wirering....I dropped the reg.board.
And no bother,thats why were here.learning,sharing.just keep on.
Jan
Im using a 18-0-18 V/180 V/A trafo:for both channels,10 A rectifier,2*10000uF caps and a cap-multiplier for each channel.Vout:ca.24V
Why exactly 22V ? Works fine with 24V.
Trafo for the regulater board (Updated Power Supply) :min.24-0-24V/min.100V/A.
The regulator and the cap-multiplier will both need cooling,not sure if the finns on this enclosure can handle it with the pwr.trans.
Introducing more;heat,potentially noice from IC's,wirering....I dropped the reg.board.
And no bother,thats why were here.learning,sharing.just keep on.
Jan
Thanks again, Jan!
Why 22V? Because of that PS Geoff has published in a link i posted above. I am aware that various voltages are used on that amp. Got feeling that Iq is more critical then egsact amount of volts. Course, it is depending with each other, but...
And yes, will not put psu elements on same heatsink. Guess that output devices can put those heatsinks to the limit all by its own demands.
Amp PCB's are related to this schematic:
The Class-A Amplifier Site - JLH Class-A Update
But PSU schematic and PCB are not the same as Geoff sugested. That is why i would like to make PS on proto boards in one hand, an in other - it is diy after all. Altough I will buy most of ready to go components.
Why 22V? Because of that PS Geoff has published in a link i posted above. I am aware that various voltages are used on that amp. Got feeling that Iq is more critical then egsact amount of volts. Course, it is depending with each other, but...
And yes, will not put psu elements on same heatsink. Guess that output devices can put those heatsinks to the limit all by its own demands.
Amp PCB's are related to this schematic:
The Class-A Amplifier Site - JLH Class-A Update
But PSU schematic and PCB are not the same as Geoff sugested. That is why i would like to make PS on proto boards in one hand, an in other - it is diy after all.
Altough I will buy most of ready to go components.
Thank you a lot!
Almost everybody acting in principle: "If more is good then too much must be perfect".
Therefore ignorants like me got complex of inferiority when start to calculating manufacturing prices. :lol:
About luck - i sure need it but am in no worry when i know where to ask.
Hi Siliconray. I've come to where I need more boards, hehe, but might I Com with a suggestion if you ever decide to change the pcb layout? Make the solder pads a tad larger. The are ok now, but i wouldn't mind them being a bit larger for times when you need to resolder, etc. Otherwise, the boards are just awesome.
Ever thought of making a pcb for the 40W version with 4xmj15003 transistors per channel?
Ever thought of making a pcb for the 40W version with 4xmj15003 transistors per channel?
Hi SiliconRay, I have finally got around to starting with my JLH amps and have discovered why some of the people might have been having problems with their pre-assembled boards. Mine has two BD139 (Q3 & Q8) transistors soldered on instead of one (Q8) being the BD140; these were ordered and delivered in Sept/Oct 2012. The components for the two unassembled PCBs are fine.
I'm also one of those people who needs to find time for my hobby. Life and work gets in the way. I'll give feedback and pictures once they are up and running.
Regards, Kevin - Pretoria, South Africa
I'm also one of those people who needs to find time for my hobby. Life and work gets in the way. I'll give feedback and pictures once they are up and running.
Regards, Kevin - Pretoria, South Africa