Ask the Audio Doctor: September–October 2000, Page 2
Hi Doctor,
Should I stick to my receiver or buy a power amp? I have a Sony STR DA777 ES receiver. I watch movies 30% and listen to music 70% (more or less). I bought the following speakers:
Front B&W N805 Center B&W HTM2 Rear Mirage OM-R2 Sub REL Storm III
I thought that the receiver is becoming the weak link in my system, so I tried to add a power amp such as Rotel 1095 or ATI 1506, but Sony’s support is saying that it is not possible to add the amp and use the receiver as a pre amp. I like the receiver very much (I got for less than $1000), but I would love to listen to the best sound I could get from my speakers. Any recommendation?
Dear Mahab, According to the Sony Web site, the STR-DA777ES is supposed to have pre-outs. This should allow you to hook-up an external power amp to the receiver and bypass the internal amplifiers, essentially turning the receiver into a preamp/processor/tuner.
Even if it only has pre-outs for the front left and right channels, considering that you use your system mostly for music, this will provide you with a great upgrade and boost in overall performance.
Check out the rear panel again or bust out the manual. Although I have never looked behind a 777ES, the few ES receivers I have used, all had provisions for bypassing the internal amps via a set of pre-out RCA jacks. If the 777ES does not have any, then you’ll have to make a decision – keep it or sell it. Good luck and thanks for reading Planet HiFi. – gk
Hey doc,
I currently have a Kenwood KRX-1000 receiver. I really love the receiver and I would hate to part with it. However, with DTS and dolby digital, I feel I being left behind. I have come across various sites that will "upgrade" my receiver. My question is whether this is the only solution I have or not. There seems to be inputs for 5.1 channels, but I’m wondering if this is more for an external amplifier. I am slowly upgrading my system, I will be purchasing an external dts/ac-3 decoder and reasonable DVD player, so I want to make sure it will work with my current system. Please help and thanks!
– GITESH PATEL
Dear Gitesh, If your receiver has the requisite 5.1 channel inputs, then you are all set to go. If you are unsure whether or not these inputs are for the purpose of adding an outboard digital surround decoder, check out the manual or ask the dealer when you start looking to buy the decoder and DVD player. If you find that your receiver is not capable of taking a 5.1 input from an outboard decoder, getting your receiver physically upgraded may be your only other option besides buying a new receiver. I understand that MSB Technology will perform such an operation. They are listed inside our PHF Recommended Links page. Good luck and thanks for reading Planet HiFi. – gk
Dear Doctor,
I have a Resolution Audio CD50. I also have A joule Electra pre-amp and Merlin VSM-SE speakers with battery BAM. In addition I have Rega Planar 3 with an Ear phono pre with volume control. And finally my amps are Atma-Sphere MK II M-60s. When I play the CDP or the Turntable directly into the Atma-Spheres (Balanced from CDP), I get incredible resolution. It feels like you are sitting in front of each instrument or voice. However, the bass tends to be a little thin and there is a lack of "impact" when there should be and possibly a thinness, or lack of girth to the human voice and other instuments.
When I go through the Joule(The BAM is in the tape loop), I lose some detail but gain the impact and bass. Is there anyway to keep as much detail and still get the gain throughout the musical spectrum. If I didn’t list direct from source to Amp, I don’t think I would have missed it. But now that I know that detail is there, I feel kinda stuck between a razor and a soft place!
Oh yes, my cabling is all silver, except some copper in the tape loop for the BAM. The BAm adds to the BAss, but makes the highs recede ever so slightly.
– Steve
Dear Steve, You are experiencing a phenomenon that many audiophiles have been wrestling with for some time. Passive pre-amps also provide a similar dilemma to the one you are experiencing when driving your amps directly from the analog outputs of your CD player – subdued bass and dynamics coupled with increased resolution. One way around this problem is to go with a CD player with a built-in volume control such as the Wadia line of CD players or a number of Krell units. Although I have not listened to them in my system, a few magazine reviewers and Planet HiFi readers have claimed that this design approach provides the listener with extreme high resolution and bass impact and big powerful sound. So, unless you are willing to audition some new products (either different pre-amps or CD players with digital or analog volume control), you’ll have to try and forget about marrying the best of both worlds. I am not aware of any quick fix. Good luck and thanks for reading Planet HiFi. – gk
Steve Replies: Thanks! I do have a Resolution CD50 which has an analogue volume control, they say it has the same op amps as the Rowlands? So I think there is some bass etc, just I get more from the JOule pre amp. Oh well its a matter of preference I suppose. Thanks again – Steve
Dear Sir,
I am writing to you to seek your advice and assistance in deciding whichn dac to partner the Sony DVP S-7000 used as transport. I read your review of this DVP partnered with Ed Meitner’s BiDat. In your review you also mentioned that the new Ed Meitner’s dac(awesome) would be out soon – which Museatex dac are you refering to. Recently in Planet Hifi, Gregory Kong reviewed the Birdland Audio Odeon-Lite dac, have you heard this dac?. Compared to the BiDat, which would you advise I partner the Sony with? Because your review was before the Odeon-Lite and in your review yor said the Sony/BiDat combo is hard to beat. I am treating this as a friendly personal advice which I hope you will be happy giving. I thank you in advance. – regards
– Suhaimi
Dear Suhaimi, Clement Perry no longer writes for Planet HiFi. You can check out new product announcements from Museatex at http://www.cadvision.com/ads/museatex.htm. As for your DVP-S7000, look out for a review of the 24/96 upgrade from MSB Technology in a future issue of PHF. Dennis Hartwick has sent his 7000 in and should receive it shortly. This upgrade will allow the 7000 to output 24/96 through its digital outs and send the signal to a 24/96 capable DAC (like the Odeon-lite but unlike the new Museatex DAC’s). Good luck and thanks for reading Planet HiFi. – gk
Suhaimi Replies: Hi Gregory, Thank You for responding my e-mail to Clement Perry. And thank you for your input. regards, Suhaimi
Dear Doctor,
I was wondering if you could give me some advice about what speakers would sound best with my system. I have a Proceed AMP2 amplifier, and a Proceed PRE pre-amp. What speakers would best bring out the musical qualities of this system. Thank You
– Jennifer
Dear Jennifer, Considering that your Proceed combination has a lean and fast sonic signature, I would look for a loudspeaker that is fuller and smoother sounding with good bass extension. This would provide a nice match and a complementary musical balance to the sound. I would recommend staying away from aggressive loudspeakers, especially ones with a ripe top-end. Electrostatics would work well, as would some planar loudspeakers. You may want to consider auditioning the Martin Logan Aerius i ($2,500/pr), an excellent speaker with exceptionally smooth treble and a high resolution midrange. Bass is fairly tight and quick but does not extend much below around 40 Hz. If you have a small to medium sized listening room, and do not listen to rock or pop music, these could be the ticket. Of course, Martin Logan has a number of larger (and more expensive) models to choose from if you fall in love with the sound but require a larger speaker to fill up the room. If you are looking for something a bit smaller in size, I would also look into the B&W 805 ($2000/pr) or the B&W CDM1 SE ($1100/pr). Both have a sweet upper register and smooth frequency response throughout each of the loudspeakers’ ranges. The Sonus Faber Concertos would be a prime candidate as well ($1850/pr) with great imaging and soundstaging. They require gobs of power to sound their best but the 150 watt/ch AMP 2 should be more than sufficient for the task. Good luck and thanks for reading Planet HiFi. – gk
Dear Sirs,
I am looking for an Magnum Dynalab signal sleuth, preferrably used. Do you have one available? Price? 230V / 50 Hz operation? Regards,
– Piet
Dear Piet, Sorry, we cannot help you with your request. Please try some of the hifi classifieds sites such as http://www.audiogon.com or http://www.audioshopper.com. Good luck and thanks for reading Planet HiFi. – gk
Hello:
I’m looking to upgrade my system. This is what I have right now.
AMC CD8a cd player Cambridge Dacmagik 2 DAC Audio quest ruby speaker cables, Moster cables for the rest Adcom 535 and 555II amp and preamp Von Schweikert Research VR2000 for speakers
The system is in the basement which is about 14′ x 22′. I would like to upgrade my system with new preamp and amp but not bust the budget. (The babies still need to eat you know) What would be a good match? How about XLR balanced I/O? Can it improve the sound? Thanks in advance
– John A Wakefield
Dear John, Using balanced interconnect cables may improve the quality of your sound by lowering the noise floor through common-mode rejection. But in my experience, the improvements are slight and many times non-existent. I have found that components designed with a fully balanced topology benefit most from using an XLR or balanced connection. In the case of your Adcom combination, I would suggest remaining with single-ended or RCA connections.
As for upgrading your amp and preamp, depending upon your budget, you may want to consider remaining with Adcom. The current Adcom GFA-5802 ($1750) and GFP-750 ($1250) are fabulous sounding components and very well-made. The amplifier retains much of the sonic character of your 555 mkII, but improves upon it in every possible way, including bass slam and control. The preamp, in my opinion is the real gem. When placed in passive mode, the sound becomes both transparent and extremely smooth. No glare or hardness to the top-end at all. And if you want a little more ‘oomph’ to the sound when you want to rock the neighbors, just switch it into active mode. For less money, you may want to go the integrated amplifier route. You loose a bit of flexibility, but you gain value by eliminating an extra chassis and set of interconnects. Look into the awesome Arcam Alpha 10 ($1600) or Arcam FMJ A22 ($2000). Both units are based off the same design, with the A22 containing a heavy gauge aluminum cover, aluminum faceplate, all-around better cosmetics, and the same upgrade options as the Alpha 10. The sound is fast and revealing with great pace, rhythm, and bottom-end. All good points for your listening preferences. Good luck and thanks for reading Planet HiFi. – gk
John Replies: Thank you very much for the advice. I am going to audition the components you mentioned plus the Brystons. Hope you had a great 4th. – John
Dear Doctor
Dave Johnson wanted to know how upsampling a standard CD would improve sound because it was already encoded. You answered the wrong question by telling him what we all already know: upsampling an analog signal would result in greater waveform accuracy. I’d like to know how CD manufacturers propose to improve the sound by "upsampling" an already digitized signal! Thanks
– Ron
Dear Ron, I do not quite understand your question. Manufacturers such as Meridian and Birdland Audio do indeed upsample the signal in the digital domain through the use of digital signal processing. If I misled Mr. Johnson, yourself, or our readers – my apologies. I should have made it clearer. But perhaps Bel Canto Design’s explanation of how their new DAC 1 "improves" the sound of ordinary 16/44.1 CD’s, may be more helpful to you. The following information is taken directly from their Web site at http://www.belcantodesign.com. Quantization noise in the Digital to Analog conversion process. The input Sample Rate Converter used in the DAC1 increases the bit depth of 16 bit data to 24 bits, adding 8 bits of dither to the original 16 bits of data to bring the data depth up to 24 bits. The dither pushes the quantisation residue at the DAC output more than 40 dB below the noise floor of the original 16-bit conversion. This dither method reduces DAC quantisation residue without any addition to the original recording’s noise floor, as occurs with other dither and resolution enhancement processes. All inputs, from 16 bits at 32, 44.1, or 48 kHz to the new 24/96 material is processed by the DAC at 24 bits/96 kHz. Original 24/96 recordings are processed with no additional dither; the noise floor of the original recording or the microphones will effectively provide dither of the last few bits of any 24-bit recording. The result of this process insures that the quantisation noise floor of the DAC1 is well below any 16 to 24 bit original.
Sample Rate Converter Primer
Sample Rate Conversion (SRC) has been mentioned in this white paper and is critical to the performance of the DAC1. SRC is a digital signal processing technique which uses digital filters to change the sample rate of a digital audio signal from, for example, 44.1 kHz to 96 kHz. The SRC in the DAC1 is a new device designed to reduce residual noise products of this conversion to more than 120 dB down. This level is more than 20 dB below the noise floor of all 16-bit recordings and is even below the noise floor of all analog recordings and 24/96 sources. When processing 24/96 material the residue from the SRC is more than 128 dB down, below the thermal noise floor of the best DAC chips. All of the advantages of doing sample rate conversion described above are realized without an increase in noise or distortion from the SRC process. This custom DSP IC uses the latest technology operating with 24-bit precision and the equivalent processing capability of a powerful microprocessor.
In addition, a white paper of the recently released Assemblage D2D-1 sample rate converter is available for download on the Sonic Frontiers Web site at http://www.partsconnection.on.ca/public_html/tpc/d2dconvert.html. This product sounds very interesting as it is a digital to digital device, lying between your transport and DAC. Again, like the previously mentioned companies, Sonic Frontiers is attempting to "improve the sound by "upsampling" an already digitized signal", among other things (reducing jitter, slow roll-off filtering, interpolation of bits, etc.) Hope this helps. – gk
Ron Replies: Appreciate your reply, Rgds, – Ron
Dear Audio Doctor,
I recently read Clement Perry’s review of the Sony DVP-S7000. In the review Perry refers to the DVP-S7000 as a wonderful transport. I don’t know what a transport is and why it is different from a regular CD player. I was hoping you could explain this to me. Also, I would like to know how to make my DVP-S7000 sound as good as Perry’s. Thank you.
– Ali Rabbani
Dear Ali, A CD player is essentially made up of two pieces. One part reads the digital information from the compact disc (via laser from the pits in the CD’s layers) and the second part converts the digital information into analog information so that the rest of your system can process it (amplifier, loudspeakers, etc.) A transport is a separate component that performs only the first described function. A digital to analog converter (DAC or D/A) takes care of the second part of the process. Clement Perry was using the Sony DVP-S7000 in order to read the information from the disc only (even though it has the capabilities to both read and convert the data – hence the ‘player’ designation). Any CD player that has a digital output can be utilized in this manner. By connecting a 75 ohm rated digital cable from this digital output to the digital input of an outboard DAC (completely separate chassis), we can perform the same exact function of a one-box CD player but with improved performance (usually). This is a great way to keep your digital front-end updated without having to sell your CD player and purchase a new one. Keep the player and use it as a transport but upgrade the internal DAC section of the player by bypassing it and sending the signal to an external DAC.
If you want to have your DVP-S7000 sound as good as Clement’s, you will need to purchase an external DAC and a digital cable. At the time, Clement was using an Ed Meitner BIDAT (no longer in production), but you can use any number of high quality DAC’s. Just make certain that you audition the components before purchasing them – they do sound different from each other and performance varies. Good luck and thanks for reading Planet HiFi. – gk
Doctor:
I am trying to improve the sound of a Sony 300 Disc changer (Not ES). The purchase of this was basically just an experiment because it is a lot more fun than a single tray unit. My system consists of B&W Nautilus 804’s driven by a McIntosh MC162 amp and Mac C712 preamp. The Sony only has a Toslink output (The ES only has this as well which is one of the reasons I did not get it). I will put BDR cones under it shortly but I also want to use a DAC. Since these are becoming passe, there are a lot of good used options out there but I do not know where to turn. Since this isn’t that good of a machine, I do not know if it will benefit me putting a lot of money into it but I desperately want to improve it. I also have a Pioneer 702 LD player with a coax digital out that will benefit from the DAC as well. Here are some options that I am considering:
AMC DAC8 (new) $99.00 Audio Alchemy DITB (used) $100.00 Soundstream DAC-1 (new) $150.00 Theta Cobalt (used) $225.00 Theta Pro Prime IIa (used) $475.00 Adcom GDA-600 (used) $250.00 Aragon D2AMK2 (used) $350.00
I really like the old reviews of the Theta Pro Series and the build of the unit but question if my cd player is revealing enough to make these justifiable. Also, should I consider an anti-jitter device w/ separate power supply such as the Theta Chroma in the line-up as well? Thanks
– Craig Mcmurtry
Dear Craig, I agree that the 300 disc changer’s ability to act as a CD storage unit is a very appealing proposition. But, as you already know, the sound from these units can be a bit thin, cold and sterile. An outboard DAC would be an excellent add-on and certainly worth the cost of the upgrade. A jitter box would also improve the sound quality but may not be worth the extra cost, especially if the DAC has some sort of jitter attenuation built in (PLL’s, stringently controlled clocks/ oscillators). The Sony would benefit more from a jitter box than the LD player because Toslink has a much more narrow transmission bandwidth, and therefore carries much higher levels of jitter compared to coaxial or BNC. I would take a ‘wait and see attitude.’
From your list of potential purchases, I would personally look hard at a brand new Soundstream DAC-1. At $150, you really can’t go wrong. Obviously, the Pro Prime IIa at $475 is a bigger investment with probably much better sound than the Soundstream. But do you really want to invest $450 more into your CD player? It’s your call. As a wild card, I would also check out the CAL Sigma II. I just spotted one on AudiogoN for $300 (obo). You may be able to grab this excellent tubed DAC for $250 or even $200. The warmer and fuller sound from this piece would mate very well with the less appealing sound from the Sony CD player. And you can upgrade it to 24/96 status in the future! Good luck and thanks for reading Planet HiFi. – gk
Dear Doctor,
I was wondering where I can get a hold of a Meitner Bidat DAC?
– Ali Rabbani
Dear Reader, You can still purchase Meitner products from the Museatex Web site. Just visit our Planet HiFi Links page at http://www.planethifi.com/planethifi/links.htm and click through the appropriate link under ‘Manufacturers’. Another option would be to keep checking the second-hand classifieds/auction sites such as http://www.audiogon.com and http://www.audioshopper.com. Good luck and thanks for reading Planet HiFi. – gk
Dear Doctor Kong,
Thank you for your time. I’ll fill my scrip for the audio textbooks A.S.A.P. Also, the window treatments are next. I noticed you did not comment on my speaker wire and interconnects, not being critical, just observant. 2 follow-up questions,
1)Do you know of any web sites where I can check used/demo audio equipment values ?
2) Recommendations for CD players/Amp combos for above average sound quality ?
Dear Reader, Try http://www.audiogon.com and http://www.audioshopper.com as well as the venerable http://www.ebay.com
– Mike Mellin
I like the Rega Planet ($800), Marantz CD-67se (now the CD-6000ose, $500), and the Pioneer DV-525 ($250) CD/DVD player as a transport driving the MSB Link DAC III ($600 with 24/96 upsampling upgrade). As for amps, I dig the sound of the NAD C340 ($450??), Decware SE84B ($500, tubed but very low-powered), Adcom GCS-510 ($500 but now discontinued), Marantz PM-17 ($1,200). There are others, but not enough time to list them all. – gk
Mike Replies: Thank you and a good day to you Sir. Will update you down the road. – Mike M., Batavia,Il
Hi,
I have a nice 200 watt home stereo and the main speakers are at 6 Ohms. What would happen if I took some 8" woofers (meant to be used in car audio) that are 4 Ohms and used them? Could I do this without hurting my stereo and getting the right sound from them?
Dear Paul, It depends on the load tolerance of your amplifier. Is it stable into 4 ohm loads (and below 4 ohms for brief periods of time)? Although a speaker may be rated as having an impedance of 4 ohms, it is usually the nominal impedance. An amplifier must also take into consideration the minimum impedance it will face as well as how much the impedance fluctuates over the entire frequency range. I cannot recommend using car speakers with a home audio amplifier. Unless you are very familiar with specifications of both the speakers and the amplifier, it is a risky and potentially hazardous maneuver. In addition, car speakers rarely sound better than home audio speakers. And be forewarned if you are considering using them without inserting them inside a loudspeaker cabinet or enclosure. The sound will be absolutely horrible. I hooked up a pair of Infinity Kappa car speakers to an Adcom amplifier and was paralyzed by the noise that shot from the metal cones. Good luck and thanks for reading Planet HiFi. – gk
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This page forms a chronological bridge between the 1999 column and Ask the Audio Doctor in January–February 2001.