Carl_Huff said:
No problems Carl, just wondered if you had a full component list by manufacturer; would be good to build it as you intended, No probs if you dont... I will piece one together.
Will be putting in a short order for the board by end of day. I just wanted to make sure the latest version was V2.0 06.02.09, please confirm.
Doylep,
I actually do have a complete BOM with part numbers from Mouser and Digikey. Give me a couple of days to get that rounded up and posted. I should be able to post it over the coming weekend.
The files posted for download are the latest.
I actually do have a complete BOM with part numbers from Mouser and Digikey. Give me a couple of days to get that rounded up and posted. I should be able to post it over the coming weekend.
The files posted for download are the latest.
Carl,
I sure would like to see someone step up to the plate and get a small GB going. I have a dozen amp design pcb's but nothing with the thermal trak devices. Like I said earlier I am in for four.
I hope to one day build them all. Have to make retirement plans. Is a sailboat in the Bahamas a proper place to build amps?
Please excuse the OT. Tad
I sure would like to see someone step up to the plate and get a small GB going. I have a dozen amp design pcb's but nothing with the thermal trak devices. Like I said earlier I am in for four.
I hope to one day build them all. Have to make retirement plans. Is a sailboat in the Bahamas a proper place to build amps?
Please excuse the OT. Tad
Doylep,
Of late I have been using www.ourpcb.com. Pricing has been moving around a bit of late but they are easy to work with and always do a good job.
Tad,
I have no problem sponsoring a group buy but the fact is no one has built this specific layout. I really think we need to validate this layout as successful before we go the expense of a big board spin. Wouldn't you agree?
Of late I have been using www.ourpcb.com. Pricing has been moving around a bit of late but they are easy to work with and always do a good job.
Tad,
I have no problem sponsoring a group buy but the fact is no one has built this specific layout. I really think we need to validate this layout as successful before we go the expense of a big board spin. Wouldn't you agree?
Carl,
A beta test board would be the prudent approach. We will just have to wait a little while longer.
I am by no means prepared to build another amplifier. I have too many already to build.
Tad
A beta test board would be the prudent approach. We will just have to wait a little while longer.
I am by no means prepared to build another amplifier. I have too many already to build.
Tad
Definately, the way to go. I have a couple of prototype boards on the way, hopefully be able to do a build next week. Already have heatsinks and ps ready to go.
Carl,
Did you manage to find that BOM ?
Carl,
Did you manage to find that BOM ?
Hi Guys
Please correct me if I am wrong, you all know I'm a speaker guy!
Looking at the input,
The 100 Ohm resister and 820pf cap provide 6dB roll off above 1.9MHz.
The 47uF and 12K resistor provide high pass 6dB above 1.4 Hz.
Since I need 6dB filters (PLLXO) at 500Hz can't I just alter the two caps as appropriate. I worked out a figure of 26.5nf to replace the 47uf. 27nf is the preffered value and is very close. 3.3uf to replace the 820pf.
I'm sure I'm missing something
It can't be this easy.
Terry
Please correct me if I am wrong, you all know I'm a speaker guy!
Looking at the input,
The 100 Ohm resister and 820pf cap provide 6dB roll off above 1.9MHz.
The 47uF and 12K resistor provide high pass 6dB above 1.4 Hz.
Since I need 6dB filters (PLLXO) at 500Hz can't I just alter the two caps as appropriate. I worked out a figure of 26.5nf to replace the 47uf. 27nf is the preffered value and is very close. 3.3uf to replace the 820pf.
I'm sure I'm missing something
It can't be this easy. Terry
Wavebourn said:
Thank you Wavebourn, I've saved that link. Very handy calculator.
So my values are correct, the question is now can I simply replace these components or will it affect other areas.
Terry
I don't know the ULD, but many amplifiers like to see a low input impedance. Changing the DC blocking cap to one a few decades smaller will significantly increase the source impedance. This may impact on the distortion and noise performance and maybe in other ways as well.
AndrewT said:
Hi Andrew,
Yes this will happen, but won't the impedance only rise in the part of the band we don't want. I would like to do without a buffer stage if possible. Does any one know how the ULD design will cope.
Terry
impact of source impedance
I don't know, I'm not a designer nor qualified in electrics/electronics.pheonix358 said:
Capacitor Selection
Prototype Update.
I would like to solicit some input in component selection for the prototype. If anyone should like to nominate a particular type/manufacturer for the caps or any other component not fully specified for that matter please let me know, note that collector caps are not fully described on the schematic so I have added an entry. I am about to source these components and I don't mind spending a little extra if we have consensus.
I am just the solder monkey and prototype financier so all input will be appreciated. Please refer to the schematic and layout in earlier post for the details.
ps. I am expecting the boards any day now...
Component list
C1 = 47uF NP
C2 = 820pF
C3 = 47uF 35V
C4 = 47uF 35V
C5 = 220uF 16V
C6 = 100pF 100V
C7 = 470uF 63V
C8 = 100nF
C9 (Collector Caps) = 100nF
C10 = 100nF
C11 = 1uF
C12 = 150nF 400V
C13 = 1000uF 63V
C14 = 100nF
C15 = 1000uF 63V
C16 = 100nF
D1 =
D2 =
D9 = DQ12
D10 = DQ13
D11 = DQ15
D12 = DQ16
D13 = DQ14
D14 = DQ17
L2 = 6.8µH
Q1 = 2SA970
Q2 = 2SA970
Q3 = BC550C
Q4 = BC550C
Q5 = BC556B
Q6 = BC556B
Q7 = 2SB649A
Q8 = 2SC2240
Q9 = 2SD669A
Q10 = MJE15030
Q11 = MJE15031
Q12 = NJL3281D
Q13 = NJL3281D
Q14 = NJL3281D
Q15 = NJL1302D
Q16 = NJL1302D
Q17 = NJL1302D
R1 = 1M
R2 = 12K
R3 = 10R
R4 = 100R
R5 = 100R
R6 = 6K8 1W
R7 = 100R
R8 = 68R
R9 = 2K2
R10 = 100R
R11 = 470R
R12 = 68R
R13 = 6K2
R14 = 6K2
R15 = 510R
R16 = 2K2
R17 = 100R
R18 = 12K
R19 = 4K7
R20 = 2K2
R21 = 200R
R22 = 200R
R23 = 100R
R24 = 220R
R25 = 100R
R26 = 10R 1W
R27 = 0.22R 5W
R28 = 0.22R 5W
R29 = 0.22R 5W
R30 = 0.22R 5W
R31 = 0.22R 5W
R32 = 0.22R 5W
R33 = 6.8R 1W
Prototype Update.
I would like to solicit some input in component selection for the prototype. If anyone should like to nominate a particular type/manufacturer for the caps or any other component not fully specified for that matter please let me know, note that collector caps are not fully described on the schematic so I have added an entry. I am about to source these components and I don't mind spending a little extra if we have consensus.
I am just the solder monkey and prototype financier so all input will be appreciated. Please refer to the schematic and layout in earlier post for the details.
ps. I am expecting the boards any day now...
Component list
C1 = 47uF NP
C2 = 820pF
C3 = 47uF 35V
C4 = 47uF 35V
C5 = 220uF 16V
C6 = 100pF 100V
C7 = 470uF 63V
C8 = 100nF
C9 (Collector Caps) = 100nF
C10 = 100nF
C11 = 1uF
C12 = 150nF 400V
C13 = 1000uF 63V
C14 = 100nF
C15 = 1000uF 63V
C16 = 100nF
D1 =
D2 =
D9 = DQ12
D10 = DQ13
D11 = DQ15
D12 = DQ16
D13 = DQ14
D14 = DQ17
L2 = 6.8µH
Q1 = 2SA970
Q2 = 2SA970
Q3 = BC550C
Q4 = BC550C
Q5 = BC556B
Q6 = BC556B
Q7 = 2SB649A
Q8 = 2SC2240
Q9 = 2SD669A
Q10 = MJE15030
Q11 = MJE15031
Q12 = NJL3281D
Q13 = NJL3281D
Q14 = NJL3281D
Q15 = NJL1302D
Q16 = NJL1302D
Q17 = NJL1302D
R1 = 1M
R2 = 12K
R3 = 10R
R4 = 100R
R5 = 100R
R6 = 6K8 1W
R7 = 100R
R8 = 68R
R9 = 2K2
R10 = 100R
R11 = 470R
R12 = 68R
R13 = 6K2
R14 = 6K2
R15 = 510R
R16 = 2K2
R17 = 100R
R18 = 12K
R19 = 4K7
R20 = 2K2
R21 = 200R
R22 = 200R
R23 = 100R
R24 = 220R
R25 = 100R
R26 = 10R 1W
R27 = 0.22R 5W
R28 = 0.22R 5W
R29 = 0.22R 5W
R30 = 0.22R 5W
R31 = 0.22R 5W
R32 = 0.22R 5W
R33 = 6.8R 1W
resistors are resistors, just make sure each is asked to dissipate <50% of rating and preferably <10% of rating. 1% metal film does for most upto 1W rating.
Capacitors come in many flavours.
electrolytic, both polar and bipolar
metallised film
foil and film
mica
ceramic, either NP0/C0G , or high dielectric
don't use paper or tantalum
Usually the component values will determine which is used where.
Semiconductors, keep them unchanged.
Capacitors come in many flavours.
electrolytic, both polar and bipolar
metallised film
foil and film
mica
ceramic, either NP0/C0G , or high dielectric
don't use paper or tantalum
Usually the component values will determine which is used where.
Semiconductors, keep them unchanged.
AndrewT said:
Andrew,
thanks for your reply, do you have any preference for capacitor makes Eg:
film: DEC,WIMA,Solen.
Electros, Nichicon, Black gates.
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