zares
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Post by zares on Dec 16, 2013 16:19:16 GMT
I've seen this PDF a lot of times and didn't see that there are schematic to 681F, sorry, my bad and thank you. You wrote that you had the MKIII in 662F but you didn't like it and suggest me to do MKI or MKII. So what was wrong with the MKIII in 662F?
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zares
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Post by zares on Dec 22, 2013 11:37:09 GMT
What about these values (662F)?
r1 = r2 = 47 Ohm r3 = r4 = 51 Ohm (56 Ohm if guitars and cymbals feel too bright) C1 = C2 = C3 = C4 = 1.33uF (1uF // 330nF) L1 = L2 = L3 = L4 = 470uH
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solderdude
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Post by solderdude on Dec 22, 2013 19:02:27 GMT
the mkIII lowers the bass as well which is not really needed for F versions as they already have much lower bass levels.
I did not like the HD662 at all, not before modding and after modding and found it a bit 'closed' sounnding with 'weird' highs. I sold them to someone that didn't care (he uses them as a monitor)
Don't have one lying around any more so cannot recommend nor measure one to see what needs to be done. You can tinker with some values when the filter is external and see if you can get it to sound good enough. When the caps are increased in size the filter frequency lowers. Do note that ithe frequency doesn't lower by a factor 1.33 if you increase the caps with a factor 1.33 but the filter frequency shifts with the SQRT of 1.33
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Post by madmac on Dec 23, 2013 11:28:19 GMT
I noticed that I still think the 681-B has too much highs. I plugged it in on my Macbook and thought "hey, sounds great", but then I realised I'd made a EQ setting for my Sony MDR570 CD which had strongly cut highs and strongly boosted lows and that setting was still active. When I deactivated it the 681-B's sound was awfull.
It's like said here many times: it's hard to remember sound.
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zares
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Post by zares on Dec 23, 2013 23:00:12 GMT
Thx for all posts, Frans, I really appreciate. As I have no idea about electronics I have to ask you one more question. Do these values cut bass or I can use them? I only want to have cutted trebles in 662F, because the amount of it is enough for me. Bass cutting depends which schematic is used, right? Or does it depend on values? On my logic I should use schematic for 681F and use these values: r1 = r2 = 47 Ohm r3 = r4 = 51 Ohm (56 Ohm if guitars and cymbals feel too bright) C1 = C2 = C3 = C4 = 1.33uF (1uF // 330nF) L1 = L2 = L3 = L4 = 470uH I want to use these because some guy who uses 662F told me they are ok. I am going to use 662F to listening to the metal music on DAP. The 681 Red with AKG K240 pads (nice job, Frans, with pads comparison!) and MKIII filter will be playing metal music too, but on FiiO E09K + E07K. 662F are nice in metal. With filter they will be amazing! I think that 681 with filter will be awesome too. I just don't want to mess it up, so I want to make sure if these values only cuts trebles or not. I would be very grateful for all answers Merry Xmas!
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solderdude
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Post by solderdude on Dec 24, 2013 8:11:57 GMT
This filter won't cut the bass, it only addresses the treble peak.
The HD6xx-F versions do not need to have the bass reduced.
Merry Xmas as well...
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solderdude
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Post by solderdude on Dec 24, 2013 8:21:37 GMT
I noticed that I still think the 681-B has too much highs. I plugged it in on my Macbook and thought "hey, sounds great", but then I realised I'd made a EQ setting for my Sony MDR570 CD which had strongly cut highs and strongly boosted lows and that setting was still active. When I deactivated it the 681-B's sound was awful. It's like said here many times: it's hard to remember sound. You can reduced the highs a bit further if needed by changing some values. This 'widens' the area in which the filter is active. replace L3-L4 with 1mH (was 470uH) replace C3-C4 with 330nF (was 680uF and in the earlier filter this was 1uF) also you can increase the value of R3-R4 to 68 Ohm but would keep it at 56 Ohm myself.
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Post by goldenboy on Mar 24, 2014 1:15:30 GMT
Hi Solderdude, Can you help me with the right parts of the filter needed. I've read the HD681 filter pdf and i believe the first Schematics on the list is the MK III version? 1. L1 - L4 Rdc < 2.6 Ohms, Current >0.4A 2. R1 - R6 metalfilm rated between 0.4 & 0.6W 3. C1 - C4 Ceramic multilayer NP0/C0G or X7R or film type. 4. C5 - C6 47uF/25V NonPolar (Bipolar) electrolytic I can order from this website: www.newark.com/?CMP=e-96de-00001000
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Post by chinook9 on Mar 24, 2014 1:33:58 GMT
Hi Solderdude, Can you help me with the right parts of the filter needed. I've read the HD681 filter pdf and i believe the first Schematics on the list is the MK III version? 1. L1 - L4 Rdc < 2.6 Ohms, Current >0.4A 2. R1 - R6 metalfilm rated between 0.4 & 0.6W 3. C1 - C4 Ceramic multilayer NP0/C0G or X7R or film type. 4. C5 - C6 47uF/25V NonPolar (Bipolar) electrolytic I can order from this website: www.newark.com/?CMP=e-96de-00001000I can't answer you question for Newark but I ordered the following parts from Mouser and they were correct for the HD681 filter to be used with low output resistant equipment: Fixed Inductors 470uH 0.28A 2.5ohms Metal Film Resistors - Through Hole 56Ohm 3/5W 50PPM Metal Film Resistors - Through Hole 27Ohm 3/5W 50PPM Multilayer Ceramic Capacitors MLCC - Leaded 0.68uF 100volts X7R +/-10% Aluminum Electrolytic Capacitors - Leaded 47UF 25V SU BI-POLAR The Mouser stock numbers in the same order listed are/were: 871-B82144A2474J 279-LR1F56R 279-LR1F27R 810-FK26X7R2A684K 667-ECE-A1EN470U Thought this might help.
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Post by goldenboy on Mar 24, 2014 2:34:41 GMT
Hi Solderdude, Can you help me with the right parts of the filter needed. I've read the HD681 filter pdf and i believe the first Schematics on the list is the MK III version? 1. L1 - L4 Rdc < 2.6 Ohms, Current >0.4A 2. R1 - R6 metalfilm rated between 0.4 & 0.6W 3. C1 - C4 Ceramic multilayer NP0/C0G or X7R or film type. 4. C5 - C6 47uF/25V NonPolar (Bipolar) electrolytic I can order from this website: www.newark.com/?CMP=e-96de-00001000I can't answer you question for Newark but I ordered the following parts from Mouser and they were correct for the HD681 filter to be used with low output resistant equipment: Fixed Inductors 470uH 0.28A 2.5ohms Metal Film Resistors - Through Hole 56Ohm 3/5W 50PPM Metal Film Resistors - Through Hole 27Ohm 3/5W 50PPM Multilayer Ceramic Capacitors MLCC - Leaded 0.68uF 100volts X7R +/-10% Aluminum Electrolytic Capacitors - Leaded 47UF 25V SU BI-POLAR The Mouser stock numbers in the same order listed are/were: 871-B82144A2474J 279-LR1F56R 279-LR1F27R 810-FK26X7R2A684K 667-ECE-A1EN470U Thought this might help. The part # 871-B82144A2474J is searchable and other do not match or unavailable but this should help. Thanks.
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solderdude
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Post by solderdude on Mar 24, 2014 5:54:54 GMT
inductor = B82144A2474J = (Newark 517070) capacitor = C330C684K5R5TA = (Newark 2112944) 47uF = NP35V476M8X11.5 = (Newark 1236671) or ECEA1HN470U (Newark 9696652)
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Post by goldenboy on Mar 24, 2014 15:59:28 GMT
inductor = B82144A2474J = (Newark 517070) capacitor = C330C684K5R5TA = (Newark 2112944) 47uF = NP35V476M8X11.5 = (Newark 1236671) or ECEA1HN470U (Newark 9696652) Thanks for the part numbers SD! I may get an original 681 later on and preparing for the filters together with the EVOs in one purchase. Btw, what is the difference of MKII and MKIII in Schematics for 681? I don't see the guide in pdf's... Can you send it by email or post it here?
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solderdude
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Post by solderdude on Mar 24, 2014 16:34:48 GMT
the mkI only removed the excess treble and left the bright character as it was.
The mkII is similar to the bottom schematic on page 9 of the article with the exception that it had somewhat more attenuation of the treble region than the original one. This made the mkII much darker sounding, more like a bass HD650 in character.
The mkIII also added the bass filter and the highs filter was between mkI and mkII.
If you have an HD681 and like the amount of bass and only want the treble lowered simply use the bottom schematic on page 9.
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Post by goldenboy on Mar 24, 2014 16:49:35 GMT
Thanks for the quick replies. I can't wait to try this out and doing the filter mods for the first time.
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Post by goldenboy on Mar 31, 2014 22:41:26 GMT
I noticed that I still think the 681-B has too much highs. I plugged it in on my Macbook and thought "hey, sounds great", but then I realised I'd made a EQ setting for my Sony MDR570 CD which had strongly cut highs and strongly boosted lows and that setting was still active. When I deactivated it the 681-B's sound was awful. It's like said here many times: it's hard to remember sound. You can reduced the highs a bit further if needed by changing some values. This 'widens' the area in which the filter is active. replace L3-L4 with 1mH (was 470uH) replace C3-C4 with 330nF (was 680uF and in the earlier filter this was 1uF) also you can increase the value of R3-R4 to 68 Ohm but would keep it at 56 Ohm myself. Can i use the 68 Ohm resistor to replace the 56 Ohm instead to lower down the highs without replacing the L3-L4 to 1mH and C3-C4 to 330nF?
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