Gentlemen
Thank u all for pening down your valuable thoughts & experiences. I can definitely now see that I need to get down to some serious mods of the DITB to realise its "hidden values" totally overlooked by AA people. Unfortunately, the DITB's stock chassis is so tiny that it doesnt allow much. So I am contemplating chucking this chassis & moving onto a brandnew larger one immediately.
Thank u all for pening down your valuable thoughts & experiences. I can definitely now see that I need to get down to some serious mods of the DITB to realise its "hidden values" totally overlooked by AA people. Unfortunately, the DITB's stock chassis is so tiny that it doesnt allow much. So I am contemplating chucking this chassis & moving onto a brandnew larger one immediately.
AndrewT is absolutely correct ... the NE5532 and/or the NE 5534 should NOT be used for a substitute for the OP275 or any of the other previously discussed op-amps = NOT PIN COMPATIBLE = zzzzzzttttt .... 
(Besides that, the '5534 does not really have much going for it = a very old design and not anywhere near useful in modern audio circuits. Bandwidth on NE5534 is anemic, slew rate is too low, etc.)
...
As for Arugp's original question and latest response re: " the DITB's stock chassis is so tiny that it doesnt allow much. ...", I might suggest that he limit his work to 1) adding more capacitance to the power rails as per StephenSank's suggestions (et al) ... and ... 2) possibly swapping the chip op-amp out for something a little bit better or not.
Surely there is room enough for these upgrade(s).
(Besides that, the '5534 does not really have much going for it = a very old design and not anywhere near useful in modern audio circuits. Bandwidth on NE5534 is anemic, slew rate is too low, etc.)
...
As for Arugp's original question and latest response re: " the DITB's stock chassis is so tiny that it doesnt allow much. ...", I might suggest that he limit his work to 1) adding more capacitance to the power rails as per StephenSank's suggestions (et al) ... and ... 2) possibly swapping the chip op-amp out for something a little bit better or not.
Surely there is room enough for these upgrade(s).
Hmmm!! I've been thinking whole of today as to how to go about the mods of my DITB & I did open up the DITB to take a good look at the PCB, how much space cum clearances etc are available once the PCB slides into the wonderfully made chassis and I kinda silently told myself - "I love this cute little box & am gonna try to fit my upgrades into this itself!"
So - with that idea and some passive parts searching on the net, I've decided to
1. Uprate the incoming PS rail caps to 1000uF with 1uF bypass instead of the stock 220uF with 0.1uF bypass
2. Add 470uF lytic with 1uF PP to the OpAmp supply pins
3. Add 470uF lytic with 1uF PP to the DAC chip analog supply
Sticking to Stephensanks & FastEddy's recommendations, I decided to go with Nichicon lytics and hopefully am confident that will manage to get them fit inside the DITB's original casing. Am presently sticking to the stock OP275 & observe for a while before trying out other OpAmps.
Is there anything I've missed out here?? Or any suggestions frorm you extremely helpful guys on the lytic or PP values?? I am surely looking forward to some great low freq response which the DITB currently doesnt deliver. Is there a possibility it will after this above mentioned upgrade?
Your valuble comments will be most appreciated.
By the way, does the output impedance change from what its now? Also, how can I get a higher output voltage from the now 2.65V (0dBFS).
So - with that idea and some passive parts searching on the net, I've decided to
1. Uprate the incoming PS rail caps to 1000uF with 1uF bypass instead of the stock 220uF with 0.1uF bypass
2. Add 470uF lytic with 1uF PP to the OpAmp supply pins
3. Add 470uF lytic with 1uF PP to the DAC chip analog supply
Sticking to Stephensanks & FastEddy's recommendations, I decided to go with Nichicon lytics and hopefully am confident that will manage to get them fit inside the DITB's original casing. Am presently sticking to the stock OP275 & observe for a while before trying out other OpAmps.
Is there anything I've missed out here?? Or any suggestions frorm you extremely helpful guys on the lytic or PP values?? I am surely looking forward to some great low freq response which the DITB currently doesnt deliver. Is there a possibility it will after this above mentioned upgrade?
Your valuble comments will be most appreciated.
By the way, does the output impedance change from what its now? Also, how can I get a higher output voltage from the now 2.65V (0dBFS).
"
1. Uprate the incoming PS rail caps to 1000uF with 1uF bypass instead of the stock 220uF with 0.1uF bypass = Good idea, in almost every case, this gadget or others.
2. Add 470uF lytic with 1uF PP to the OpAmp supply pins = Consult w/StephenSank on this re: exact values, etc. ... but I am sure this is a good choice.
3. Add 470uF lytic with 1uF PP to the DAC chip analog supply = Also a good idea (if there is physical room).
"
1. Uprate the incoming PS rail caps to 1000uF with 1uF bypass instead of the stock 220uF with 0.1uF bypass = Good idea, in almost every case, this gadget or others.
2. Add 470uF lytic with 1uF PP to the OpAmp supply pins = Consult w/StephenSank on this re: exact values, etc. ... but I am sure this is a good choice.
3. Add 470uF lytic with 1uF PP to the DAC chip analog supply = Also a good idea (if there is physical room).
"
AndrewT said:
Duly noted.
At the same time I must inject, the NE5532 is interchangeable with the most popular dual op amps used in todays audio. I've swapped it with most and it's delivered far superior results in comparison to it's competition.
It may be an old op amp but by far the best overall performer and closer specs to a 12AX7 tube compared to any other dual op amp out there be it the 4558, 2604 or 2228.
In fact it's specs are near identical.
.
.
Hi all.
nice to see some more info on the DITB. I have one, completetely unmodded, but I've been contemplating the Kal Rubenstien mods for a while.
Another mod is discussed here;
http://www.1388.com/doctor/jonopinion/14022001/index.html
He uses the DITB's AD1865 I(current)-out pins, loaded with 900ohm resistors, instead of the V-outs.
I assume this would drop the voltage seen by the output-stage considerably, and hence the actual line-out voltage.
But I wondered if this might sidestep the need to up the 5v rails to 12v in the first place, given that one of the weaknesses KR identified was the DITB's opamps having to produce a 2.4v output from a 5v rail?
nice to see some more info on the DITB. I have one, completetely unmodded, but I've been contemplating the Kal Rubenstien mods for a while.
Another mod is discussed here;
http://www.1388.com/doctor/jonopinion/14022001/index.html
He uses the DITB's AD1865 I(current)-out pins, loaded with 900ohm resistors, instead of the V-outs.
I assume this would drop the voltage seen by the output-stage considerably, and hence the actual line-out voltage.
But I wondered if this might sidestep the need to up the 5v rails to 12v in the first place, given that one of the weaknesses KR identified was the DITB's opamps having to produce a 2.4v output from a 5v rail?
DrFrankenstein: " ... I must inject, the NE5532 is interchangeable with the most popular dual op amps used in todays audio. ..."
Yes it is, and for that purpose, substituting for other Dual Op-Amps, it is as good as it used to get.
However, the single channel version, the '5534, is not pin for pin compatible with the OP275 (or most other popular 8-pin DIP configurations) ... thus = Zzzzzzzttt ... The '5534 won't work at all.
Yes it is, and for that purpose, substituting for other Dual Op-Amps, it is as good as it used to get.
However, the single channel version, the '5534, is not pin for pin compatible with the OP275 (or most other popular 8-pin DIP configurations) ... thus = Zzzzzzzttt ... The '5534 won't work at all.
FastEddy said:DrFrankenstein: " ... I must inject, the NE5532 is interchangeable with the most popular dual op amps used in todays audio. ..."
Yes it is, and for that purpose, substituting for other Dual Op-Amps, it is as good as it used to get.
However, the single channel version, the '5534, is not pin for pin compatible with the OP275 (or most other popular 8-pin DIP configurations) ... thus = Zzzzzzzttt ... The '5534 won't work at all.
Yes this was brought to my attention easily 4 posts ago
The NE5532, is, at best, an upgrade from the old 4558. How anyone could think it remotely close in sound performance to an OPA2604 or OP275 is quite unimaginable. I don't even pause for a microsecond throwing them in the trash can when replacing them with OPA2134's or etc. Even the old workhorse M5218 is a better sounding chip.
I have never seen an AA DITB equipped with an AD1865. This would preclude 12V output supply, since that chip is limited to 5V for both digital & audio ps. The DITB's that I have seen/owned without a pair of AD1860 have had the AD1864, which is identical to the AD1865, but with 12v audio section ps rating.
I could see a definite advantage to bypassing any of the above dac chips' internal I/V opamp, but for the sake of using an OPA2134 or OPA2604 external I/V stage. I may do this on the DITB I have coming, which I will be transferring to a larger chassis enclosure.
I have never seen an AA DITB equipped with an AD1865. This would preclude 12V output supply, since that chip is limited to 5V for both digital & audio ps. The DITB's that I have seen/owned without a pair of AD1860 have had the AD1864, which is identical to the AD1865, but with 12v audio section ps rating.
I could see a definite advantage to bypassing any of the above dac chips' internal I/V opamp, but for the sake of using an OPA2134 or OPA2604 external I/V stage. I may do this on the DITB I have coming, which I will be transferring to a larger chassis enclosure.
In every guitar application I've tried it in, the 5532 gives the best results. That includes numerous stages in 2 amps and a half dozen pedals. The 2604 being next and the 2228 being 3rd in that line. The major difference being the 2604 and 2228 have a bit warmer or fatter tonal qualities but the 5532 delivering the most clarity and outperforming the other two at extreme volumes.
Now Hi Fi, I can't say.
Now Hi Fi, I can't say.
DrFrankenstein said:
Hi DrFrankenstein
Precisely my opinion , the NE5532 is the more transparent and true to the source (for the best and for the worst ...
)The only op amp in the same league is the 797.
You can easily test the truthfulness to the source of any op amp via a null test...using the set up of post #8 ,at:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=13415
Regards
Using these older types of op-amps where the gain is less than 20db or so is fine = guitar first stage of gain & microphone pre-amps, etc. ... but I would offer caution when trying to build a phono pre-amp = the bandwidth of the '5534 & 5532 is a little anemic ... and I certainly would not recommend using these in an EQ and especially in a DAC = even a 16bit DAC will require more than 100 db overall gain = way out of bounds for the '5532 type.
Just came across this remark from one of the forums:
OPA2134
I would say that this Op-Amp has the worse imaging than others that I have tested. Very narrow, narrower than my PCDP output. Very narrow space between the singer and the musical instruments, sometime feel like putting my head in a bucket. It only good in bass, nothing else. So for some music from MIDI, which doesn't need imaging at all, this Op-Amp is fine. It has big bass and thick midrange, which is good. The treble is a bit 'short', means bell's sound will sound shorter than the AD8620 or OPA2228. Ok, I have no intention to make it sounds like a bad Op-Amp. OPA2134 is a good Op-Amp, very DIYer friendly, and they have nice sound color of which I like. My complaint is only the narrow imaging, that's all.
The good : Big bass and thick midrange. Nice color of sound.
The bad : Poor imaging.
Application:
I think this Op-Amp need bright, transparent, and wide imaging headphone to balance it's narrow imaging characteristic. This Op-Amp is a NO NO for people who demand good imaging, probably another good alternative for those who like music from MIDI / electronica, and like BIG bass.
----------------------------------------------
I am kinda curious if this is TRUE. Stephensank can comment on this as he replaced the OP275 with this opamp. Anybody else tried it?? Please report a feedback. Imaging & soundstaging are important to me and this is where the DITB is a champion too.
Cheers!
OPA2134
I would say that this Op-Amp has the worse imaging than others that I have tested. Very narrow, narrower than my PCDP output. Very narrow space between the singer and the musical instruments, sometime feel like putting my head in a bucket. It only good in bass, nothing else. So for some music from MIDI, which doesn't need imaging at all, this Op-Amp is fine. It has big bass and thick midrange, which is good. The treble is a bit 'short', means bell's sound will sound shorter than the AD8620 or OPA2228. Ok, I have no intention to make it sounds like a bad Op-Amp. OPA2134 is a good Op-Amp, very DIYer friendly, and they have nice sound color of which I like. My complaint is only the narrow imaging, that's all.
The good : Big bass and thick midrange. Nice color of sound.
The bad : Poor imaging.
Application:
I think this Op-Amp need bright, transparent, and wide imaging headphone to balance it's narrow imaging characteristic. This Op-Amp is a NO NO for people who demand good imaging, probably another good alternative for those who like music from MIDI / electronica, and like BIG bass.
----------------------------------------------
I am kinda curious if this is TRUE. Stephensank can comment on this as he replaced the OP275 with this opamp. Anybody else tried it?? Please report a feedback. Imaging & soundstaging are important to me and this is where the DITB is a champion too.
Cheers!
" OPA2134 I would say that this Op-Amp has the worse imaging than others that I have tested ..."
See: http://focus.ti.com/lit/ds/symlink/opa2134.pdf ... Note the design considerations re: "offset voltage trim" & "output DC voltage drift". Page 8 shows how to resolve this in a gross manner for better results ... not doing so in your layout and design will cause all manner of problems, especially with "imaging". Also since TI says the "OPA134 series op amps operate with power supplies from ±2.5V to ±18V with excellent performance. ..." it may be that the particular implimentation (board design) may have design flaws that resulted in this "worse imaging". Example: if this op-amp series does not have those close coupled 10 nF caps (0.01 uF), all kinds of "imaging" problems will erupt. I would go further and use plastic (poly) 0.1 uF caps here = even better bass response and plenty of guts for the high end ...
(This op-amp was specifically designed for quality audio work, especially as a pre-amp and active filter boost or cut (EQs) ... and in active crossovers! I doubt that Burr-Brown (TI) would bother building this op-amp series without giving at least some serious attention to audio quality.)
See: http://focus.ti.com/lit/ds/symlink/opa2134.pdf ... Note the design considerations re: "offset voltage trim" & "output DC voltage drift". Page 8 shows how to resolve this in a gross manner for better results ... not doing so in your layout and design will cause all manner of problems, especially with "imaging". Also since TI says the "OPA134 series op amps operate with power supplies from ±2.5V to ±18V with excellent performance. ..." it may be that the particular implimentation (board design) may have design flaws that resulted in this "worse imaging". Example: if this op-amp series does not have those close coupled 10 nF caps (0.01 uF), all kinds of "imaging" problems will erupt. I would go further and use plastic (poly) 0.1 uF caps here = even better bass response and plenty of guts for the high end ...
(This op-amp was specifically designed for quality audio work, especially as a pre-amp and active filter boost or cut (EQs) ... and in active crossovers! I doubt that Burr-Brown (TI) would bother building this op-amp series without giving at least some serious attention to audio quality.)
As fasteddy implies, it is very possible, and I would say probable, that the OPA2134 trial was done with poor peripheral hardware/circuit design. I generally install these chips while also upgrading drasitcally the quality & size of the power supply & other components. This chip has positively the best imaging, tonal richness & transparency of any chip I have ever heard, regardless of application.
I have even used 2134's in a few guitar amps, which I don't normally work on, e.g., a Johnson Millenium for the studio next door to my shop. That particular amp, which was a digital modeling amp, used 27 dual opamp chips, most of which were 5532 & 4560. The client was extremely pleased with how much better the amp sounded. Personally, I don't think electric guitar is a good instrument to judge opamps by, unless that is your only use for opamps. Many guitar people swear by the JRC NJM4558 as the ultimate. Might be the worst sounding chip ever for music playback, but I have no difficulty believing it's great for electric guitar applications. So, those two guys recommending the 5532 may certainly have their points, but not in any credible way can their opinions be related to music reproduction, which I gather is the focus of this particular forum.
I have even used 2134's in a few guitar amps, which I don't normally work on, e.g., a Johnson Millenium for the studio next door to my shop. That particular amp, which was a digital modeling amp, used 27 dual opamp chips, most of which were 5532 & 4560. The client was extremely pleased with how much better the amp sounded. Personally, I don't think electric guitar is a good instrument to judge opamps by, unless that is your only use for opamps. Many guitar people swear by the JRC NJM4558 as the ultimate. Might be the worst sounding chip ever for music playback, but I have no difficulty believing it's great for electric guitar applications. So, those two guys recommending the 5532 may certainly have their points, but not in any credible way can their opinions be related to music reproduction, which I gather is the focus of this particular forum.
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