What loudspeakers are you using?
I'd be interested to hear anyone's reports of this amp with different speakers. Good,bad?
With a fullrange driver I'm convinced it should be great (how about some of those Gallo A'Divas?) -- but I'm looking at a bi-amped system (passive crossover in Linn loudspeaker) and wondering whether that'll work good...
I'd be interested to hear anyone's reports of this amp with different speakers. Good,bad?
With a fullrange driver I'm convinced it should be great (how about some of those Gallo A'Divas?) -- but I'm looking at a bi-amped system (passive crossover in Linn loudspeaker) and wondering whether that'll work good...
I think I am getting close
Sorry about the large image, I just want people to be able to see things clearly.
I think this is just about ready...
Edit: Forgot the GND trace back to star ground for the LM318
Fixed it.
Sorry about the large image, I just want people to be able to see things clearly.
I think this is just about ready...
Edit: Forgot the GND trace back to star ground for the LM318
Fixed it.An externally hosted image should be here but it was not working when we last tested it.
analog_sa said:
You're Right. But I was thinking about some trick 'round this... that's not easy, though.
mmmh...
let' see... 
maybe... could something like this work?before power-on (initial status):
- a first relay keeps the output shorted (this one -together with some fuse in series with the rectifier- is the one that will take care of speaker protection in case of any major fault with DC at the output...);
- a second relay keeps a local NFB loop around the LM318 closed; this (temporary) loop will take care of keeping the 318 output (and thus the global output) at zero during the power-on transients;
power-on sequence:
- circuit is powered on, and given time to settle down;
- the first relay is activated. The output is no longer shorted, and the global NFB loop become effective. There may be a minor (?) transient, but the local loop is still in place and should avoid weird things from happening... :-?
- after some time to allow for the circuit to settle down, also the second relay is activated and the temporary local loop around the LM318 is removed. The global loop is now in place and effective, so again there should be no problems... :-?
- ok, time to light up a "ready" LED!
Unless I have overlooked something, I guess it should work...
Mauro, what do u think? Any better idea?
Last chance for review.
Unless I here there is a problem with this 2 sided layout in the next couple of hours this is what I will order for the beta test.
Cheers!
Russ
Unless I here there is a problem with this 2 sided layout in the next couple of hours this is what I will order for the beta test.
Cheers!
Russ
An externally hosted image should be here but it was not working when we last tested it.
Two so far
I am running a Rev A with my full range 15 ohm Lowthers in a folded TQWT. Works great.
Tried it Sunday on a Daedulus or close speaker. The is a five driver unit with maybe four crossovers. It also sounded great. The owner of these maybe was being nice, but said it was as good as he had heard the speakers sound.
It sure could play loud. I estimate it was playing in the 90 - 95 dB range. Much louder than I listen at home.
BTW, those are nice speaks. Dovetail construction and solid wood cabinets, not plywood. Too many drivers for me though. I am happy with one.
George
inguz said:
I am running a Rev A with my full range 15 ohm Lowthers in a folded TQWT. Works great.
Tried it Sunday on a Daedulus or close speaker. The is a five driver unit with maybe four crossovers. It also sounded great. The owner of these maybe was being nice, but said it was as good as he had heard the speakers sound.
It sure could play loud. I estimate it was playing in the 90 - 95 dB range. Much louder than I listen at home.
BTW, those are nice speaks. Dovetail construction and solid wood cabinets, not plywood. Too many drivers for me though. I am happy with one.
George
OK beta testers, I have looked the boards over the best I can, I don't see any reason not to order them. Please remeber you are beta testing prototypes, and while the circuit is well tested, this PCB design is new, so while I fully expect it to be just fine, there could be problems I cannot see. So please be diligent and review the layout.
Here is the list of beta testers:
SmellOfPoo
rabstg
hayenc
Brian Donegan
saltnpeppah
maf_au
All I can manage right now is sending the PCBs, but I will try to work one on one with a couple of you to get you the things you need.
I have each of you down for 2 boards apiece,
If you want more than 2 let me know its no problem, just let me know.
The cost will be as follows
Each board is 10.50 with shipping to me.
So two will be $21.00 even plus shipping costs.
I will figure $5.00 to continental US and $6.00 everwhere else as long as I can send it airmail post or Global Priority.
Please email me with any comments and for payment details.
Once I have all the payments lined up I will order the boards.
Cheers!
Russ
Here is the list of beta testers:
SmellOfPoo
rabstg
hayenc
Brian Donegan
saltnpeppah
maf_au
All I can manage right now is sending the PCBs, but I will try to work one on one with a couple of you to get you the things you need.
I have each of you down for 2 boards apiece,
If you want more than 2 let me know its no problem, just let me know.
The cost will be as follows
Each board is 10.50 with shipping to me.
So two will be $21.00 even plus shipping costs.
I will figure $5.00 to continental US and $6.00 everwhere else as long as I can send it airmail post or Global Priority.
Please email me with any comments and for payment details.
Once I have all the payments lined up I will order the boards.
Cheers!
Russ
partslist for rev C monoblocs
Part Value Package Library Position (inch) Orientation
AC1 TEST2 faston (3.9125 1.882374) R270
AC2 TEST2 faston (3.9125 0.807374) R90
B1 SKB50 rectifier (3.670874 1.324996) R270
C1 220uf E5-8,5 rcl-Russ (0.332319 0.619925) R180
C2 220uf E5-8,5 rcl-Russ (0.8125 0.619874) R180
C3 10000uf EB30D rcl-Russ (2.875 0.732374) R270
C4 100nf C075-052X106 rcl-Russ (0.335248 1.169874) R180
C5 100nf C075-052X106 rcl-Russ (3.4375 1.332374) R90
C6 100uf E5-8,5 rcl-Russ (1.95 1.432374) R0
C7 100nf C050-030X075-RUSS rcl-Russ (1.7 1.782374) R270
C8 10000uf EB30D rcl-Russ (2.875 1.932374) R270
C9 220uf E5-8,5 rcl-Russ (0.8375 2.282374) R90
C10 22pf C025-024X044 rcl-Russ (1.1625 1.957374) R90
C11 100uf E5-8,5 rcl-Russ (2.075 1.932374) R180
C12 220pf C025-024X044 rcl-Russ (1.4875 2.269874) R270
C13 1uf C102_152-062X184 rcl-Russ (0.525 2.682374) R0
C14 220uf E5-8,5 rcl-Russ (1.7 3.069874) R180
C15 22uf E2,5-7 rcl-Russ (1.4125 2.669874) R270
C16 100uf E5-8,5 rcl-Russ (1.8 2.432374) R180
C17 100nf C050-030X075-RUSS rcl-Russ (0.575 0.994874) R0
C18 100nf C050-030X075-RUSS rcl-Russ (0.275 0.994874) R180
C19 100nf C050-030X075-RUSS rcl-Russ (1.9125 1.682374) R180
C20 100nf C050-030X075-RUSS rcl-Russ (1.825 1.982374) R270
C30 1nf C050-024X044 rcl-Russ (0.25 2.132374) R180
C32 150pf C025-024X044 rcl-Russ (0.9375 1.744874) R0
C34 10pf C025-024X044 rcl-Russ (1.2875 1.419874) R270
D2 1N4001 D-7.5 diode (3.7875 2.232374) R0
D3 1N4001 D-7.5 diode (3.7875 2.357374) R0
D4 1N4001 D-7.5 diode (2.425 2.819874) R270
IC1 LM318N DIL08 linear (1.425 1.782374) R180
IC2 LM3886T/TF TO220-11-RUSS NAT_SEMI_POWER (0.275 1.682374) R90
JP1 1X02 pinhead (0.1 2.757374) R270
LED - + 1X02 pinhead (3.889752 2.729748) R270
OG TEST2 faston (2.125 3.119874) R0
OUT TEST2 faston (1.375 1.207374) R0
PGND TEST2 faston (3.9125 1.332374) R270
Q1 BC639 TO92-LINE transistor-small-signal (2.3 2.794874) R90
Q2 BC546A TO92-EBC transistor-npn (1.825 2.782374) R90
Q3 BC546A TO92-EBC transistor-npn (1.325 3.144874) R0
R1 1K 1W 0414/15_RUSS rcl-Russ (1.469248 0.494874) R90
R2 33K 0207/10 rcl-Russ (0.6125 0.2375) R180
R3 .47R 7W MNS-5 resistor-power (0.9375 1.357374) R0
R4 1K 1W 0414/15_RUSS rcl-Russ (1.875 0.932374) R180
R5 22K 0207/10 rcl-Russ (0.5 1.682374) R270
R6 47K 0207/10 rcl-Russ (0.875 1.882374) R180
R7 12K 0207/10 rcl-Russ (0.875 2.007374) R180
R8 22K 0207/10 rcl-Russ (0.25 2.257374) R180
R9 47K 0207/10 rcl-Russ (0.25 2.382374) R0
R10 390R 0207/10 rcl-Russ (0.25 2.507374) R0
R11 1R 0207/10 rcl-Russ (1.5125 2.132374) R0
R12 3.3K 0207/10 rcl-Russ (1.2125 2.394874) R90
R13 100K 0207/10 rcl-Russ (1.1 2.394874) R90
R14 470 1W 0411/12 rcl-Russ (3.5875 2.919874) R90
R15 75K 0207/10 rcl-Russ (0.95 3.044874) R180
R16 75K 0207/10 rcl-Russ (0.95 3.182374) R180
R19 10K 0207/10 rcl-Russ (0.95 2.882374) R0
R20 47K 0207/10 rcl-Russ (1.4 2.894874) R180
R21 220K 0207/10 rcl-Russ (2.025 2.7875) R90
R22 8.2K 0207/10 rcl-Russ (2.1375 2.787496) R90
R23 6.8K 0309/12-RUSS rcl-Russ (3.525 2.482374) R0
R37 3.3K 0207/10 rcl-Russ (0.6 2.044874) R90
R39 470K 0207/10 rcl-Russ (1.55 1.507374) R180
R42 270R 0207/10 rcl-Russ (0.9 1.607374) R180
R43 22K 0207/10 rcl-Russ (1.55 1.332374) R180
REL-1 JQC-21FF-24 JQC_RUSS relay (2.9 2.882374) R180
ZD1 12V 1W DO41Z10 diodes (1.8625 0.767626) R180
ZD2 12V 1W DO41Z10 diodes (1.8625 1.094874) R0
Part Value Package Library Position (inch) Orientation
AC1 TEST2 faston (3.9125 1.882374) R270
AC2 TEST2 faston (3.9125 0.807374) R90
B1 SKB50 rectifier (3.670874 1.324996) R270
C1 220uf E5-8,5 rcl-Russ (0.332319 0.619925) R180
C2 220uf E5-8,5 rcl-Russ (0.8125 0.619874) R180
C3 10000uf EB30D rcl-Russ (2.875 0.732374) R270
C4 100nf C075-052X106 rcl-Russ (0.335248 1.169874) R180
C5 100nf C075-052X106 rcl-Russ (3.4375 1.332374) R90
C6 100uf E5-8,5 rcl-Russ (1.95 1.432374) R0
C7 100nf C050-030X075-RUSS rcl-Russ (1.7 1.782374) R270
C8 10000uf EB30D rcl-Russ (2.875 1.932374) R270
C9 220uf E5-8,5 rcl-Russ (0.8375 2.282374) R90
C10 22pf C025-024X044 rcl-Russ (1.1625 1.957374) R90
C11 100uf E5-8,5 rcl-Russ (2.075 1.932374) R180
C12 220pf C025-024X044 rcl-Russ (1.4875 2.269874) R270
C13 1uf C102_152-062X184 rcl-Russ (0.525 2.682374) R0
C14 220uf E5-8,5 rcl-Russ (1.7 3.069874) R180
C15 22uf E2,5-7 rcl-Russ (1.4125 2.669874) R270
C16 100uf E5-8,5 rcl-Russ (1.8 2.432374) R180
C17 100nf C050-030X075-RUSS rcl-Russ (0.575 0.994874) R0
C18 100nf C050-030X075-RUSS rcl-Russ (0.275 0.994874) R180
C19 100nf C050-030X075-RUSS rcl-Russ (1.9125 1.682374) R180
C20 100nf C050-030X075-RUSS rcl-Russ (1.825 1.982374) R270
C30 1nf C050-024X044 rcl-Russ (0.25 2.132374) R180
C32 150pf C025-024X044 rcl-Russ (0.9375 1.744874) R0
C34 10pf C025-024X044 rcl-Russ (1.2875 1.419874) R270
D2 1N4001 D-7.5 diode (3.7875 2.232374) R0
D3 1N4001 D-7.5 diode (3.7875 2.357374) R0
D4 1N4001 D-7.5 diode (2.425 2.819874) R270
IC1 LM318N DIL08 linear (1.425 1.782374) R180
IC2 LM3886T/TF TO220-11-RUSS NAT_SEMI_POWER (0.275 1.682374) R90
JP1 1X02 pinhead (0.1 2.757374) R270
LED - + 1X02 pinhead (3.889752 2.729748) R270
OG TEST2 faston (2.125 3.119874) R0
OUT TEST2 faston (1.375 1.207374) R0
PGND TEST2 faston (3.9125 1.332374) R270
Q1 BC639 TO92-LINE transistor-small-signal (2.3 2.794874) R90
Q2 BC546A TO92-EBC transistor-npn (1.825 2.782374) R90
Q3 BC546A TO92-EBC transistor-npn (1.325 3.144874) R0
R1 1K 1W 0414/15_RUSS rcl-Russ (1.469248 0.494874) R90
R2 33K 0207/10 rcl-Russ (0.6125 0.2375) R180
R3 .47R 7W MNS-5 resistor-power (0.9375 1.357374) R0
R4 1K 1W 0414/15_RUSS rcl-Russ (1.875 0.932374) R180
R5 22K 0207/10 rcl-Russ (0.5 1.682374) R270
R6 47K 0207/10 rcl-Russ (0.875 1.882374) R180
R7 12K 0207/10 rcl-Russ (0.875 2.007374) R180
R8 22K 0207/10 rcl-Russ (0.25 2.257374) R180
R9 47K 0207/10 rcl-Russ (0.25 2.382374) R0
R10 390R 0207/10 rcl-Russ (0.25 2.507374) R0
R11 1R 0207/10 rcl-Russ (1.5125 2.132374) R0
R12 3.3K 0207/10 rcl-Russ (1.2125 2.394874) R90
R13 100K 0207/10 rcl-Russ (1.1 2.394874) R90
R14 470 1W 0411/12 rcl-Russ (3.5875 2.919874) R90
R15 75K 0207/10 rcl-Russ (0.95 3.044874) R180
R16 75K 0207/10 rcl-Russ (0.95 3.182374) R180
R19 10K 0207/10 rcl-Russ (0.95 2.882374) R0
R20 47K 0207/10 rcl-Russ (1.4 2.894874) R180
R21 220K 0207/10 rcl-Russ (2.025 2.7875) R90
R22 8.2K 0207/10 rcl-Russ (2.1375 2.787496) R90
R23 6.8K 0309/12-RUSS rcl-Russ (3.525 2.482374) R0
R37 3.3K 0207/10 rcl-Russ (0.6 2.044874) R90
R39 470K 0207/10 rcl-Russ (1.55 1.507374) R180
R42 270R 0207/10 rcl-Russ (0.9 1.607374) R180
R43 22K 0207/10 rcl-Russ (1.55 1.332374) R180
REL-1 JQC-21FF-24 JQC_RUSS relay (2.9 2.882374) R180
ZD1 12V 1W DO41Z10 diodes (1.8625 0.767626) R180
ZD2 12V 1W DO41Z10 diodes (1.8625 1.094874) R0
work in progress BOM for REV C
NAME VALUE Desc. Manufacturer Source Part#
AC1,AC2,OG,OUT,PGND FASTON Male AMP DigiKey A24742-ND
B1 8A 400V 8A 400V Bridge Rect. GBT804 Diodes Mouser 621-GBJ804
D2-D4 1N4001 Diode
C1,C2 220uf Radial 50V LOW ESR Electrolytic
C3,C8 10,000UF Radial 50V 30mm snap in Electrolytic cap
C4-C5 100nf 100V MKT film cap 7.5mm lead spacing
C6,C11 100uf Radial 50V LOW ESR Electrolytic
C7,C17-C20 100nf 50v MKT Film caps 5mm lead lead spacing
C9 220uf Radial 50V Electrolytic
C10 22pf Ceramic
C12,C14 220pf Ceramic
C13 1uf – 2.2uf Input cap MKT etc .4” or .6” LS
C15 22uf Radial 50V Electrolytic
C16-C20 100nf MKT 50V 5mm lead spacing
C30 1nf Ceramic
C32 150pf Ceramic
C34 10pf Ceramic
IC1 LM318N Opamp Nat. Semi.
IC2 LM3886T/TF Opamp Nat. Semi.
JP1 2 pin header 2 pin header .1” pitch
LED 2 pin header 2 pin header .1” pitch
Q1 BC639 Transistor
Q2,Q3 BC546A Transistor
R1,R4 1K 1W 1W Metal Oxide or wire wound type resistor
R2 33K 1/4W 1% metal film
R3 .47ohm 7W non-inductive vertical type power resistor
R5,R8,R43 22K 1/4W .1% metal film
R6,R9 47K 1/4W .1% metal film
R7 12K 1/4W 1% metal film
R10 390R 1/4W 1% metal film
R11 1ohm 1/4W 1% metal film
R12 3.3K 1/4W 1% metal film
R13 100K 1/4W 1% metal film
R14 470ohm 1W Metal Oxide or wire wound type resistor
R15 75K 1/4W 5%
R16 75K 1/4W 5%
R19 10K 1/4W 5%
R20 47K 1/4W 5%
R21 220K 1/4W 5%
R22 8.2K 1/4W 5%
R23 6.8K 1/2W 5%
R37 3.3K 1/4W 1% metal film
R39 470K 1/4W 1% metal film
R42 270ohm 1/4W 1% metal film
REL-1 JQC-21FF-24 JQC-21FF-24 24V relay Futurlec JQC-21FF-24
ZD1,ZD2 1N4742A 12V 1W zener diode
NAME VALUE Desc. Manufacturer Source Part#
AC1,AC2,OG,OUT,PGND FASTON Male AMP DigiKey A24742-ND
B1 8A 400V 8A 400V Bridge Rect. GBT804 Diodes Mouser 621-GBJ804
D2-D4 1N4001 Diode
C1,C2 220uf Radial 50V LOW ESR Electrolytic
C3,C8 10,000UF Radial 50V 30mm snap in Electrolytic cap
C4-C5 100nf 100V MKT film cap 7.5mm lead spacing
C6,C11 100uf Radial 50V LOW ESR Electrolytic
C7,C17-C20 100nf 50v MKT Film caps 5mm lead lead spacing
C9 220uf Radial 50V Electrolytic
C10 22pf Ceramic
C12,C14 220pf Ceramic
C13 1uf – 2.2uf Input cap MKT etc .4” or .6” LS
C15 22uf Radial 50V Electrolytic
C16-C20 100nf MKT 50V 5mm lead spacing
C30 1nf Ceramic
C32 150pf Ceramic
C34 10pf Ceramic
IC1 LM318N Opamp Nat. Semi.
IC2 LM3886T/TF Opamp Nat. Semi.
JP1 2 pin header 2 pin header .1” pitch
LED 2 pin header 2 pin header .1” pitch
Q1 BC639 Transistor
Q2,Q3 BC546A Transistor
R1,R4 1K 1W 1W Metal Oxide or wire wound type resistor
R2 33K 1/4W 1% metal film
R3 .47ohm 7W non-inductive vertical type power resistor
R5,R8,R43 22K 1/4W .1% metal film
R6,R9 47K 1/4W .1% metal film
R7 12K 1/4W 1% metal film
R10 390R 1/4W 1% metal film
R11 1ohm 1/4W 1% metal film
R12 3.3K 1/4W 1% metal film
R13 100K 1/4W 1% metal film
R14 470ohm 1W Metal Oxide or wire wound type resistor
R15 75K 1/4W 5%
R16 75K 1/4W 5%
R19 10K 1/4W 5%
R20 47K 1/4W 5%
R21 220K 1/4W 5%
R22 8.2K 1/4W 5%
R23 6.8K 1/2W 5%
R37 3.3K 1/4W 1% metal film
R39 470K 1/4W 1% metal film
R42 270ohm 1/4W 1% metal film
REL-1 JQC-21FF-24 JQC-21FF-24 24V relay Futurlec JQC-21FF-24
ZD1,ZD2 1N4742A 12V 1W zener diode
Sick person
I really am eat up with this kind of thing. All parts are matched up as closely as possible in every circuit I build.
Here the LM318 and LM3886 are not matchable. These are THE most important parts. But the voltage on the zeners is next. Build a simple power supply and use a resistor to measure the voltage of the zeners. Absolute votage is not critical, just match all four per amp to achieve a little better balance.
Also if anyone wants to spend the money, I have a source for 0.01% Vishay S102 resistors. They are not 22K and 47K. They are 22.5K and 50K. I looked at Newark and these are 17.00 each. Locally they are 3.00.
I am way too slow to do the beta test. It will take me a month to build an amplifier. The production boards will be out before I finish a beta.
One more request, can the hole size be increased for some of the resistors? The ones in the relay control are too small for my old style Holcos. Here it is not critical, but the H2 and H4 have the same diameter leads.
Also the input resistors and feedback. I have 1/4 watt AB carbon comp for these that fit, the 1/2 watt are easier to source.
George
I really am eat up with this kind of thing. All parts are matched up as closely as possible in every circuit I build.
Here the LM318 and LM3886 are not matchable. These are THE most important parts. But the voltage on the zeners is next. Build a simple power supply and use a resistor to measure the voltage of the zeners. Absolute votage is not critical, just match all four per amp to achieve a little better balance.
Also if anyone wants to spend the money, I have a source for 0.01% Vishay S102 resistors. They are not 22K and 47K. They are 22.5K and 50K. I looked at Newark and these are 17.00 each. Locally they are 3.00.
I am way too slow to do the beta test. It will take me a month to build an amplifier. The production boards will be out before I finish a beta.
One more request, can the hole size be increased for some of the resistors? The ones in the relay control are too small for my old style Holcos. Here it is not critical, but the H2 and H4 have the same diameter leads.
Also the input resistors and feedback. I have 1/4 watt AB carbon comp for these that fit, the 1/2 watt are easier to source.
George