Opa1656 vs opa627 reddit forum audiophile
Opa1656 vs opa627 reddit forum audiophile. It depends very much on the circuit if a faster OP can be used. I tried a ton of headsets this month and mainly for gaming/light music. Mar 17, 2019 · 2019-04-21 2:49 pm. With OPA827 and OPA627, the second harmonic (40kHz) was larger than the fundamental wave of 20kHz, and 40kHz was regarded as the fundamental wave, so THD could The Aiyima a07 runs very cool normally but was getting pretty hot to the touch when the ambient temp was 38c. OPA2156 is also laser trimmed for lower input offset voltage. Jul 29, 2023 · Audiokarma. Dec 11, 2019 · The SIL uses small inductors on IP transistors. Mar 17, 2019 · If the impedance is high (10k ohm or higher), then a FET input op amp may be better. V6 vivid measured superb tho. • 1 yr. But of course, how they're implemented and how they interact with the sound system as a whole makes all the difference. Feb 15, 2024 · Part Number: OPA627 Other Parts Discussed in Thread: OPA1656 , OPA1642 I am in the process of restoring and upgrading several pieces of the vintage Kenwood Basic Ethan-V4hn. so I would use old school OPA2134 or LM4562. 2K unbalanced and 4. Whether that results in auditory differences, I'll leave to the listener to decide And yes, samples should be available here in a day or two once the stock becomes visible on ti. Our primary goal is insightful discussion of home audio equipment, sources, music, and concepts. Nov 25, 2015 · Ive compared the NE5532, NJM4556 and LM4562 so far. May 10, 2022 · In short, OPA1656 shows very high THD level when voltage below +-9 Volts. Mar 19, 2005 · The GBW and Slew Rate of the 627 is higher than that of the 2134 (GBW of 16mhz versus 8, and a Slew Rate of 55 V/us versus 10). 10 mins - 13 mins for the section specifically focusing on music, compared with HomePod G1. Taking advantage of a wide power supply range and mounted on a DIP8 bracket, it can replace many other models. ago. First off, I'm no audiophile and don't work in the industry at all. I feel the majority of audiophiles like ‘accurate’ bass, they do want to hear and feel the deepest frequencies, but don’t want it to be unnaturally accentuated and boomy. Mar 17, 2019 · Joined 2006. Unless there’s industry data somewhere comparing speaker sales, I’m not sure how you answer this question. • audio·phile: a person with love for, affinity towards or obsession with high-quality playback of sound and music. the differences aren't huge, but big enough to make a change worthwhile. The BA is only an indication of "grade" for certain tolerances for optimal conditions for use. I would say that if you want a quick drop in replacement to try out the Burr Brown/TI sound, pop in the 2134. I looked at the Slew Rate as my main OPA1656 SBOS901A –MARCH 2019–REVISED JULY 2019 OPA1656 Ultra-Low-Noise, Low-Distortion, FET-Input, Burr-BrownTM Audio Operational Amplifier 1 1 Features 1• Ultra-low noise: – Voltage noise: 2. For example, Aol for the OPA1656 with a 600 ohm load will have a linear output swing that is 1. Altered text SYMATTR Value OPA1656 SYMATTR Prefix X SYMATTR SpiceModel OPA1656. 8 pF, 470 ohm and 15 pF, 220 ohm were actually differences between left and right of your turntable. When we developed the OPA1656, this was also a major design target for us, and the designer and myself spent quite awhile in the lab with previous CMOS audio op amps (specifically OPA1652 and OPA1688) hunting for sources of input capacitance variation. Both BB's sound really good to me. However, I think that that alone as a regular consumer may help yall decide on a pair of good cans. ConsciousNoise5690. The common-mode rejection is identical at -116 db, and the THD specs are also quite similar Feb 29, 2008 · The LM4562 is a nice opamp and won alot of awards when it was released for the performance to price it is good. 9 nV/√Hz at 10 kHz – Current noise: 6 fA/√Hz at 1 kHz • Low distortion: – 0. I like the low noise aspect of it, though it's pretty expensive. The FET-input architecture achieves a low 2. May 15, 2022 · Member. In the 1990s, National moved the metal packaged power audio amps to plastic package for cost reduction to the customer. I prefered the sound of my DAC with the OPA1656's hands down even over the discrete op-amps. 5 metre cable at 33. #764. I used 4 Burson V6 Vivid in my Burson headphone amp but I have replaced them all with OPA1656. Set 1 produces no visual deviation at all. I did an A/B comparison to LME47920 (metal cans), burson V5i, V6 and also the Sparkos Pro discrete op-amps on one of my DAC's. Jan 2, 2021 · OPA1656 / OPA1612 / Burson V5i / OPA627 / Genuine NE5532 / Genuine Muse 02 / 0PA1622 / OPA1642 / OPA1602 The question of Op amps has already been debated on DIY audio, and I had used the OPA1656 and I think the opinions are unanimous, these Op amps are very good and seem to work the best with those amps. Jul 4, 2009 · The entire OPA627 line sounds obsolete compared against OPA828. Even at prices you may think are low, they have decent margins. 5 vs 8 nv. OPA1656 has about 6 dB more open loop gain at audio frequencies, so distortion is potentially lower. 🤷♂️ Reading the other comments here, maybe buying a whole other amp would be better, but I alread May 23, 2018 · The first and obvious conclusion: we must avoid the audiophile Burson Audio V5. There are lots of videos and forum posts of people comparing op-amps, and on this amp especially. And of course, the price on the OPA1656 is lower. Bang and olufsen were always about form follows function (the philosophy that the definition is more important than the job it for fills) so it’s not an audiophile brand it’s a designphile brand, an alternative to the overpriced brand would be KEF. OPA2156 does not, it is closer to a single pole response. 3V inside of each supply. Mar 17, 2019 · Op amp manufacturers would degenerate the input pair and so they could stabilize the op amp with a much smaller compensation capacitor, and the resulting slew rate of the op amp (determined by tail current and comp cap size) was much higher. Mar 17, 2019 · The OPA627 was released in the 90s and we're still selling them in high volume. 9 nV/√Hz at 10 kHz Jan 28, 2018 · OPA627/37 I tried both OPA627 and OPA637 in this circuit, and both were pretty much the same because of the low gain setting of the feedback resistor. So THD measurement value of -25. I’m going to solder the IC to a soic to dip adapter then plug it into the the amp. Not familiar with modern devices. Headphones are much more intimate experience. I'm also ordering OPA2134 opamps to replace the NE5532's that are stock. Below is a comparison between OPA1656 and OPA1642. A non-rail to rail input opamp (like OPA1656) would just clip at that voltage, so pick your poison. Noise and distortion wise OPA1641 or OPA827 perform better. Two schematics in parallel and eight in parallel for both 1656 and 1642 were measured. Reply. Mar 17, 2019 · When we developed the OPA1656, this was also a major design target [] This article shows the measurements I took on the OPA164x family. Note that while the OPA1656 is unity gain stable, it does have an internal compensation circuit that causes a phase wobble in the 1-10 MHz region. Sep 26, 2019 · The AIYIMA Tilear Rev 2. Disregard offset issue with +-3V power, see abnormality with +-6V. Take a look at this figure from its datasheet. Blue line - Input 1Vp-p, yellow - output. r/audiophile. It's a basement with concrete walls so that helps with baffling. The AD8620,627,637 are in a different league then the 4562. This presented itself as a more refined and detailed version of the OPA2604. They discuss a wide range of topics including music and movies, solid-state and tube audio, digital sources, DACs, turntables, tuners, tape, headphones, speakers, listening spaces, home theaters, manufacturers, and marketplaces. r/audiophile is a subreddit for the pursuit of quality audio reproduction of all forms, budgets, and sizes of speakers. Furthermore, the noise performance of the 627 is about 50% better than the 2134. Since the input signal is -34dB and the harmonics are +66dB, the distortion factor is 100dB emphasized and measured. com) I have tested the The AIYIMA Tilear Rev 2. Mar 28, 2022 · The OPA1656 can deliver 100 mA of output current, so it should be able to drive a headphone load. OPA1656: 3Mb / 38P [Old version datasheet] OPA165x Ultra-Low-Noise, Low-Distortion, FET-Input, Burr-Brown??Audio Operational Amplifiers DECEMBER 2021: OPA1656: 3Mb / 42P [Old version datasheet] OPA165x Ultra-Low-Noise, Low-Distortion, FET-Input, Burr-Brown™ Audio Operational Amplifiers REVISED SEPTEMBER 2022: OPA1656ID: 3Mb / 38P • audio·phile: a person with love for, affinity towards or obsession with high-quality playback of sound and music. 1F X7R on the backside with the shortest possible lead length. I did a big comparison test with all the top notch audio opamps including a $70 discrete opamp, I picked OPA2604 and OPA604. Now i tested opa1612 with lme49720 and 1612 is better in my opinion. They are light and comfortable". Dual customzied solution will give unmeasurable distortion (possibly -180db). I used 10 or 12 in my preamp rolling project - never a problem with Jun 8, 2023 · OPA828. You must decide where to stop because the sky is the limit. If there are more complicated parts (especially active parts) in the FB path, a faster OP can be a problem. 9 $ , they have a decent margin ? May 23, 2018 · Seems that with the cheap good NE5532P the THD+N decreased from 0. I was coming from wireless g533s as my base pair. This is my first time doing anything DIY with audio. It has the most stable input capacitance vs. $1-2,000 is better. With a FET input op amp input current noise is lower, but the input voltage noise is higher. The input is essentially shorted with 10mohm resistor in order to have a -140db control signal. form follows function. Also some opamps will exhibit crossover distortion, so the internal topology does matter. Feb 1, 2006 · The 134 series have now been superceeded by the OPA1641/2/4. (or the 2156) The opamp has good phase margin and seems quite tolerant of sub-optimal layout. (See diyaudio. 5 MHz LM4562, 55 MHz OPA2134, 8 MHz A 1 metre cable with polyethylene dielectric has its first resonance at 50 MHz, a 1. Aug 28, 2009 · In comparing the spec sheets of OPA627B and ADA4627B-1, the current noise specs are identical (1. The 2227 and 2228 are pretty laid back, like most opa's, but they are revealing and agressive like the 8620. Though I use it only occasionally mostly for tests, and it has not operated more than a couple of hours summed, the right channel started to emit high frequency hiss noise time after time, without any special reason, even if nothing is connected to the input. Nov 30, 2020. Aol for the OPA2134 with a 600 ohm load has an output swing that is 2. OPA1656 is a bit noisy at low frequencies. #12. This is why older high speed op amps and amplifiers targeting video applications have fairly high In general you get the best sound of you maintain “unity gain”, meaning the full signal strength without any boost or cut, for as much of the signal path as possible, and then control your volume from downstream. Every amp. 1nv). 9 mA of supply current to accommodate the power supply constraints of many types of audio products. 25 V to ±18 V (4. Mar 17, 2019 · So to put 1 in a baggie exactly like the OPA1656 , they charge 15,69 $ !! , to put 10 in a baggie : 130 $ !!! TI does all the work and Mouser leaches more profit off from it. The performance of the CMOS audio op amps is actually fairly close and maybe slightly better than the OPA627, which was somewhat famous for its performance in this use case. 2020-10-11 4:57 pm. the much more expensive MUSES01. I am planning to replace the NE5532 in my Burson Funk with the OPA1656. Since I am not interested in the V6 Vivid Dual that it comes with. sinadoh. Feb 11, 2021 · Yes. lib file into the related LTSPice folder 2. 9 nV/√Hz at 10 kHz Mar 17, 2019 · The OPA1641 would be slightly better. lib SYMATTR Value2 OPA1656 SYMATTR Description TI/BB Audio FET Opamp to get the same symbols as the ordenary Opamp 4. I look forward to it sounding even better. Need to keep in mind. Description for the OPA1656. the supply voltage and current draw. Mar 17, 2019 · Here there are a number of options: BJT-inputs without bias current cancellation (OPA1622), Super-Beta BJTs (OPA2210), Low voltage noise JFET and CMOS (OPA1642, OPA827, OPA828, OPA1656/2156). Many have subs integrated in their setups. Mar 17, 2019 · Even the original LM12 power op amp was in a 4 lead TO-3 metal package, with the die mounted on a heat spreader tab. Mar 17, 2019 · OPA1656 also has a pole-zero pair in the open loop gain curve to boost the open loop gain at audio frequencies (hence the 53 MHz gain bandwidth product). Dec 17, 2018 · Certainly use a socket for opamp rolling. on LTSpice load, the lengthy lib update happend. 5V inside of the positive rail . kozzyosko December 10, 2021, 10:34am 1. Last edited: May 27, 2017. There are additional poles and zeroes in its frequency response, which introduce additional lumpity bumpity behaviors in the gain-vs-frequency and phase-vs-frequency plots. As anyone tried rolling the op-amps on the new Fosi V3? Which ones did you try and what changed in comparison to the stock ones? May 23, 2018 · Opa1656 and opa1612 without tweaking have better performance than almost any discrete solution. Added a new OPA1656. . The only thing that I was a smidge disappointed by was the lack of specifics on eARC latency. #49. 0067% to 0. According to the datasheet, TI lists: BM, BP, SM, AM, AP, and AU grades. You don't have to use SA, distortion level obvious on oscilloscope screen. solderdude said: Actually the SIL opamps are pretty good. Some will argue "gaming headsets are made for extended period use. Jul 4, 2009 · New BUF634A has higher slew rate, wider BW and decreased quiescent current in wide-BW mode, and is cheaper than original 634. I think it's a matter of circuit design and implementation. asy using the ADA4627 as a template 3. Yes, we call that behavior on the OPA2156 input crossover distortion and it is present on all op amps which use a dual input stage to achieve rail-to-rail input voltage range. 2V inside the negative rail and 2. at +/-20Vdc, drawing about 8mA. This was around the time of the LM3886 getting released. 22dBc means -125. OPA1656 is positioned for audio applications: low noise and really good THD (-131dB) and high output current (100mA), but still needs a series resistor to drive capacitive loads unfortunately. Amazing value and no more urge to upgrade. More than that is better still, but the more you spend the less you get for each additional dollar. But, there are a ton of usable audio frequency op-amps, and anything other than applying actual engineering practice (such as picking parts based on "tonality" "musicality" "warmth" etc) is audiofoolerly. Some work was also done to reduce common-mode distortion in the OPA1656 when the impedances at the inputs are mismatched. OPA1656 Dual OPA DIP8 (Unit) This OPA1656 OPA from Texas Instrument offers very good performances for audio use. Sep 27, 2019 · The OPA1656 operates over an ultra-wide supply range of ±2. the ne5532 looks a bit harder, narrower and more direct, the other two a bit more relaxed and This subreddit is for the budget minded audiophile that wants to grow out of soundbars, boomboxes, mini systems, portable bluetooth, lifestyle speakers, and PC peripheral branded audio solutions. Sort by: MrWalrusGumboot. The AD8620BR, is a very nice opamp and you should be very pleased with it. Sound is more "color", and "massive". I have them measured ln violectric v200 and gain stage of o2. Not targeting Mouser here , most of the others are worse. Of course there are a number of other factors to consider, like the ability to drive the input impedance of the following circuitry with low distortion r/audiophile. These combinations should be equal to a single op-amp noise and 4 paralleled op-amps noise. I must test muses now. So you should keep your program on 100 and your OS at 100, and control the volume at the speakers. Measurements done directly on headphones-output jack (MUSES8820 + LME49600). It'll struggle a bit with 33 Ω load, though. 000035% (–129 dB) at 20 kHz Nov 30, 2021 · The output swing for Aol should be considered as it is different between the two devices. Copied the given . It has a more forward presentation, with a much wider soundstage. Nov 26, 2017 · thanks for your tips! i have tested the opa2604 and the LME49720 compared to the ne5532. consists of 2 x 10 op-amps in parallel and the two 10s are balance connected. When I have people over and crank it up, it blows everyone away. An unofficial community about Apple and all of its devices and software. 8 pF, 470 ohm works 15 pF, 220 ohm works Any perceived and measured differences between 6. Basically, the 2228, to me at least, is the perfect blend between the BB sound and the AD sound. Mar 17, 2019 · The only difference between the 1655 and 1656 is that the second amplifier has been removed from the die of the OPA1655. 5. We focus on education, discussion, and sharing of entry and mid level separate & multi component audio systems. 22dBc=548%. I keep computer at 100% and May 27, 2017 · Slew rate is faster on the OPA627, but OPA604 at over 20V/uS is plenty plenty fast for audio. This is called the law of diminishing returns. Second harmonic decreased with about 16dB and the third one with about 2dB; background noise remained identical, very low actually. Also, audiophile headphones will provide a much wider sound stage, which can go a long way as far as directional audio goes. Another surprize , you'd think considering the price and age , next gen OPA827-828 would have replaced the 627. common mode voltage that I've measured on any op amp. They also have a lower supply current than the 072 series making them safe for limited current power supplies. The effective input noise depends on both the input current noise & input voltage noise. 1 with great caps and some mod (OPA1656 / inductors update) sounds really good too. WAV is preferred for audio editing/production since it’s easier to decode and supported by nearly everything but for storing and listening to music it’s pointless. 3 MHz. Setup calibrated in dbV. 0026% vs. •. 4K balanced. There are exceptions, like the Sennheiser gaming headset that produces pretty decent sound for a pretty decent price. While emailing with a great Tech Support guy at Rotel, he suggested only one Rotel approved Mod. However, it doesn’t sound like those two chips at all! It’s very musical imo. 55), but in inverting mode only. 16. Great alternative to TPA325X / Hypex Ncore (this is subjective ) is the double Mono Merus amp. #29. Set a budget. Some soundstage improvement as well. HomePod 2: A Definitive Audiophile Review. In my case the OPA828 has been a clear upgrade to the OPA627 but the OPA1656 is an upgrade to the OPA828. I had no oscillations or instability with the OPA1656. 2017-06-04 7:42 pm. These would toast. May 19, 2017 · Joined 2006. Jan 7, 2021 · Talking about AIYIMA A07, it will end up in a dustbin soon. Really ? On a new OPA1656 that cost around 0. Not exactly universally compatible with all preamps. Both methods generally increase open loop gain up to around 65 - 100 kHz then it will taper off more quickly than a traditional single order compensated opamp. 000029% (–131 dB) at 1 kHz – 0. I spent literally days trying to find the right pair. Noise is roughly around 3-4nV. com. $500 is maybe a start, less than that is still in the realm of the possible. He said to replace the two XR5534A op amps with two AD847 op amps and to replace four 18 ohm resistors R219, R220, R225 and R226 with Sep 14, 2021 · The LM4562 is an exception, but otherwise it are the fast op-amps that JRA has trouble with: Misbehaving: OPA1656, gain-bandwidth product 53 MHz LME49990, 110 MHz OPA1612, 40 MHz Behaving well: OPA2604, 20 MHz OPA627, 16 MHz OPA2107, 4. This subreddit is for the budget minded audiophile that wants to grow out of soundbars, boomboxes, mini systems, portable bluetooth, lifestyle speakers, and PC peripheral branded audio solutions. Many more recent op amps (released after 1996) are • audio·phile: a person with love for, affinity towards or obsession with high-quality playback of sound and music. Output signal is amplified 90db. #3. OPA627 is a single channel op amp. Mar 17, 2019 · Last week TI put a preliminary datasheet online for the OPA1656, a low noise, very low distortion op amp targeting audio applications and fabricated in a CMOS process. Most of the differences look to be in the input voltage nose and open-loop voltage gain. Mar 17, 2019 · Hi John Yes, did it my way… 1. NE5532 can be configured. The latter method used in SIL was first used in the famous (Deane) Jensen 990 discrete opamp many years ago. Mar 17, 2019 · OPA1656 rolling I tried in all cases to bypass the rails with a 0. #354. FLAC is a compressed lossless codec and WAV is uncompressed. Those are also low bias FET inputs with a rail-to-rail output section for greater headroom. Jul 4, 2009 · The two others are opa2107 and opa627. 2 inwall/ceiling setup. Thanks for that recommendation. dotneck335 said: An OPA1612 has slightly better specs than an LM4562---less noise and distortion, faster, and more output voltage swing. Like many opamps, the OPA1656 does NOT have constant gain-bandwidth product. at +/-20V so minor tweaks of the power supply/voltage dropping. Two identical gain 11 amplifiers were tested. Speakers I’ve noticed commonly mentioned in audiophile discussions (in no particular order): JBL, Dynaudio, PMC, Kharma, B&W, Sonus Faber, Wilson Audio, Harbeth, Monitor Audio, Martin Logan, Klipsch, KEF, Linn Magic, Yamaha, Vienna Jul 4, 2009 · The OPA1655 is the single channel version of the OPA1656. but the difference between opa2604 and LME49720 is much smaller than the difference between these two compared to the original ne5532. So put 10 x OPA1656 in a bag to send costs 16,76 $ , to put 10 x OPA627 in a bag to send costs 130 $ . You are not “wrong“ in describing the Opa1656, it is recommended to be used in portable devices I/V stage because it has a input fet like the opa1612 and the opa1642. Dec 6, 2018 · The OPA627 is mainly good for very low input bias - usually no need for this with audio. Its compression doesn’t affect the source signal which is the reason it’s called lossless. LME49720 sound is boringand too light. 5nv/6. At least -120db thd performance. I like the 627s but prefer the OPA637 for my own system. 9‑nV/√ Hz voltage noise density and 6‑fA/√ Hz current noise density, allowing for very-low noise Dec 11, 2019 · São Paulo, Brazil. The 4627 is faster the the 627 (82v/uSec vs. I use two OPA1656 in parallel in the HP-2. LM is the best overall, it sounds the most balanced, very natural/smooth/clean, doesnt exaggerate anything but can sound lacking in impact. MusicGetsMeHard. Based on 2 customers reviews. Panning works a lot better, especially with sounds that are supposed to go behind you. Aug 15, 2010 · Originally Posted by brianlsu /forum/post/19055265 Violator, I have a dedicated cinema, 120" screen, JVC RS20 and a 7. OPA165x Ultra-Low-Noise, Low-Distortion, FET-Input, Burr-Brown™ Audio Operational Amplifiers 1 Features • Ultra-low noise: – Voltage noise: 2. 0 / 5. Audiokarma is a discussion forum dedicated to home audio and stereo systems. strangely its probably the most boring sounding one when paired with 400i but the best sounding with hd600. 1 with the following OP amps : OPA1612 OPA627 OPA1656 Burson Audio V5I genuine Mar 17, 2019 · The obvious reason why someone would buy OPA627 is: because they tried it in their equipment and perceived that the sound was best, in their opinion, compared to all other opamps they tried. It has a very good dynamic range and a low level of harmonic distortion. 6fA @100 Hz), and the voltage noise favors the 627 only slightly (4. 5 V to 36 V) on 3. I think your primary assumption “the majority of audiophiles hate bass” isn’t true. Mar 17, 2019 · The schematic, spectrum and results are given below. Dec 27, 2019 · Dec 27, 2019. The OPA1655 and OPA1656 (OPA165x) are Burr-Brown™ op amps designed specifically for audio and industrial applications, where maintaining signal fidelity is crucial. Apr 11, 2007 · The 865 already sounds pretty sweet for an older, not too expensive CDP. 1 10 100 1000 1 10 100 1k 10k 100k 1M 10M 9ROWDJH1RLVH6SHFWUDO'HQVLW\ Q9 ¥+] Frequency (Hz) C006 Product Folder Sample & Buy Technical Documents Tools & Software Sep 14, 2021 · So if I understand you correctly: 3. Mar 17, 2019 · 2022-10-15 8:53 pm. Dec 10, 2021 · DIY Audio. In addition to the lower voltage supply, I will be drilling some ventilation holes in the bottom and top of the case for better cooling. 4 pF, 1 kohm does not work 6. I bought the 2 Sparkos Labs Dual Discrete Op Amp SS3602's on sale and put in my A07 and I thought it made a big difference in clarity over stock. Newer op amps provide a far more detailed and precise sound, which in turn also results in a broader tonal range. The op amp offers a temperature range of -40°C to +125°C and is available in an 8-pin SOIC package. • 12 yr. C. More details. Not sonically different of course but good performers and can actually run on +/-24V (in case one needs opamps to go slightly above the usual +/- 18V rails) When rolling opamps having a 1GHz scope could come in handy. They also have lower THD and noise is 5. I much prefer headphones, although speakers are nice once in a while, and I generally use speakers when listening to vinyl. I'm using SpeakerCraft Cinema 5's up front and Aim7 5's in the ceiling. Generally a FET input has a higher 1/f noise corner than a BJT input. Mar 19, 2005 · Hi, Well I got my adapters and tried the 627 in my parasound preamp and the difference was almost as great as teh step up going from ad712 to opa2134 to opa627. Mar 22, 2022 · OPA1612 (soic on dil adapter board), bi-polar from input to output, again a very good opamp, which to me "sounds more balanced" top to bottom than the LME, it is just as dynamic, but just a little less obvious in the bass leading edge because the mid-range seems a little more fleshed out rich and full bodied, highs are just as good as the LME. It would be interesting to know what the input impedances are for the Sparkos and Sonic Imagery opamps. engie490 said: I noticed in Purifi's specs that the input impedance is 2. It's a relatively harmless pursuit and the price is similar to the price of a vacuum tube -- which audiophiles happily pay, and then furiously swap among Oct 11, 2001 · Behind the 2228, the 2604 is my favorite BB opamp that I have heard (I have yet to hear the 627). Mar 17, 2019 · I purchased 10 OPA1656's. eg gq wh ej tz rb ll aw pl qo