Denon PMA 1600 or Yamaha A S701, and hello

[Bernard23]

Yes, it was odd, and not what I expected. The statement isn't wrong, maybe the observation. I've heard many budget amps over the years, so thought I'd got a good idea of what's good, and not so. Maybe the yamaha was faulty, it wasn't new.
It does raise an important point though, one of the reasons why ASR is so useful is it principally challenges the product claims of the manufacturers. Its an industry that has turned self certification into an art form.

 

[ZolaIII]

@Bernard23 thing is Yamaha (in the most cases at least) still mesure it's gear and provides results (not all results but declarative one's or as mesured graphs for some speakers and subs). I have Yamaha R-N402D and on Q3030i (similar efficiency but easier to drive) speakers currently and with Volume Trim set to - 6 dB on Dolby streams or stereo with EBU R128 (-24 LUFS) on shootout I never had gone over 86 volume step (of 100).
Peple don't understand every +3 dB is W*2 and that difrence between 100 dB and 106 dB for average sensitive speakers of 85 dB is +96 W (128 vs 32).
So far old chunky AB class Yamahas that ware mesured hire actually gave more output power than declared by manufacturer.

 

[TonyJZX]

i think the 701/801 is pretty much the defacto sub $1,000 best buy for anyone after a higher power traditional integrated.

the Denon at twice the price isnt twice as good.

The other unit you may like if you have the money is the Yamaha AS1200 but at that price there's a lot more options.

 

[Bernard23]

@Bernard23 thing is Yamaha (in the most cases at least) still mesure it's gear and provides results (not all results but declarative one's or as mesured graphs for some speakers and subs). I have Yamaha R-N402D and on Q3030i (similar efficiency but easier to drive) speakers currently and with Volume Trim set to - 6 dB on Dolby streams or stereo with EBU R128 (-24 LUFS) on shootout I never had gone over 86 volume step (of 100).
Peple don't understand every +3 dB is W*2 and that difrence between 100 dB and 106 dB for average sensitive speakers of 85 dB is +96 W (128 vs 32).
So far old chunky AB class Yamahas that ware mesured hire actually gave more output power than declared by manufacturer.

Yes indeed, I understand logarithmic scales. No idea how the bigger Denon amps measure or sound, comparing prices they don't share the same price to power points. I've got the cheap entry level Denon so 45W/8ohm compared to probably the s301 at a similar price (£350 vs £400) 60W, presumably also 8ohm and 20-20K though the Yamaha spec sheet doesn't state the conditions. It's possible that Denon are under stating the power output, who knows. It goes surpringly loud without any obvious compression. I'm only missing approx 1.3dB compared to the Yamaha, which I doubt I'd notice in use. I've got tolerant neighbours, but not that accommodating.

 

[ZolaIII]

Yes indeed, I understand logarithmic scales. No idea how the bigger Denon amps measure or sound, comparing prices they don't share the same price to power points. I've got the cheap entry level Denon so 45W/8ohm compared to probably the s301 at a similar price (£350 vs £400) 60W, presumably also 8ohm and 20-20K though the Yamaha spec sheet doesn't state the conditions. It's possible that Denon are under stating the power output, who knows. It goes surpringly loud without any obvious compression. I'm only missing approx 1.3dB compared to the Yamaha, which I doubt I'd notice in use. I've got tolerant neighbours, but not that accommodating.

Actually the Denons don't mesure bad and if second harmonic whosent bad they would stay at 90 dB SINAD range @5 W but it's around 85~86. Whose interested in getting one and find partial measurements long ago. It's entirely possible denon underrated power output for that model so it actually gives more.
Yamaha didn't specify stated figures in A-S 301/501/701 rang manual but I know it's at 500 mV input. With 2.2 V input the A-S 501 gives 130W but with THD of 10%.
I like Yamahas not that Denons are bad in any way.

 

[Bernard23]

Tbh, I'm not traditionally a fan of either, in the past I've invested in NAD, Roksan and Hegel and ATC. I've always liked the 70s Japanese aesthetic though, and both, especially yamaha have that nailed. As much as I'm interested in data, it's also my day job so I'm happy to sometimes just indulge in subjective pleasure, this time round looks and the ritual matter! Heck, I've got a 1977 Technics SL-1800 up and running, and started collecting vinyl again!

 

[ZolaIII]

Well "new old" Sanken AB Yamaha amps are faithful to the old 1970's one's regarding power amplifier stages and we know that they use deacent capacitors and good power stages that's my only bias towards Yamaha.
See the figure 6 to understand why they perform best wnen input stage is authend to 400~500 mV trough Volume Trim for models that have such controls.
Post in thread 'Yamaha R-N803 Smart Receiver Review' https://audiosciencereview.com/foru...-n803-smart-receiver-review.13830/post-422668
Best regards and have a nice time.

 

[Bernard23]

Well "new old" Sanken AB Yamaha amps are faithful to the old 1970's one's regarding power amplifier stages and we know that they use deacent capacitors and good power stages that's my only bias towards Yamaha.
See the figure 6 to understand why they perform best wnen input stage is authend to 400~500 mV trough Volume Trim for models that have such controls.
Post in thread 'Yamaha R-N803 Smart Receiver Review' https://audiosciencereview.com/foru...-n803-smart-receiver-review.13830/post-422668
Best regards and have a nice time.

Do you think circuit design is generally more critical than component quality? In the context of common consumer electronics, rather than an academic question. I'm not an electronics engineer hence the ignorance, though a material engineer so have a tiny grasp of what's going on.
I ask because I'm contemplating modding a late 1990s Denon amp that I bought for peanuts. It's still all original and was refurbed by a chap close to me who is a telecoms engineer by day, whose hobby is restoring and refurbishing hifi gear. He checked and tested it before I bought it, and was thinking of asking him to upgrade a bunch of components just out of curiosity. It sounds pretty punchy as it is, 65w /8 ohm, 100w / 4ohm according to specs. I found a thread about it 9n DIY audio that piqued my interest:

Advice on upgrading a Denon PMA-925R

Hi, i am curently studying, so the funds for new HI-Fi parts are low. I have a Denon PMA-925R stereo amplifier that i am considering giving an upgrade, instead of buing a new amplifier. So i would like to have your advice on how to, and if it is a good idea? I am considering changing the two...

www.diyaudio.com

If the design / topology is beyond salvation I'll retire it.

 

[Doodski]

Do you think circuit design is generally more critical than component quality? In the context of common consumer electronics, rather than an academic question. I'm not an electronics engineer hence the ignorance, though a material engineer so have a tiny grasp of what's going on.
I ask because I'm contemplating modding a late 1990s Denon amp that I bought for peanuts. It's still all original and was refurbed by a chap close to me who is a telecoms engineer by day, whose hobby is restoring and refurbishing hifi gear. He checked and tested it before I bought it, and was thinking of asking him to upgrade a bunch of components just out of curiosity. It sounds pretty punchy as it is, 65w /8 ohm, 100w / 4ohm according to specs. I found a thread about it 9n DIY audio that piqued my interest:

Advice on upgrading a Denon PMA-925R

Hi, i am curently studying, so the funds for new HI-Fi parts are low. I have a Denon PMA-925R stereo amplifier that i am considering giving an upgrade, instead of buing a new amplifier. So i would like to have your advice on how to, and if it is a good idea? I am considering changing the two...

www.diyaudio.com

If the design / topology is beyond salvation I'll retire it.

The amp uses the Denon typical loosely regulated mains dual transformer power supply to enable power output to reach some high peaks but be loaded down on sine waves or strong musical dynamics. Dual mains transformers and 12,000 micro farad smoothing caps is decent for a 80W/ch@8R. If the power supply where to reach peaks at the quiescent voltages then the amp would be capable of ~158W/ch@8R peak output power. Not that the amp will ever reach 158W/ch@8R but for very small transients it will reach higher than the RMS figure of 80W/ch@8R. What is it that you are thinking of MOD'ing?
Nice amp. A service manual is available.

Denon PMA-925R Integrated Stereo Amplifier Manual | HiFi Engine

www.hifiengine.com

 

[Bernard23]

The amp uses the Denon typical loosely regulated mains dual transformer power supply to enable power output to reach some high peaks but be loaded down on sine waves or strong musical dynamics. Dual mains transformers and 12,000 micro farad smoothing caps is decent for a 80W/ch@8R. If the power supply where to reach peaks at the quiescent voltages then the amp would be capable of ~158W/ch@8R peak output power. Not that the amp will ever reach 158W/ch@8R but for very small transients it will reach higher than the RMS figure of 80W/ch@8R. What is it that you are thinking of MOD'ing?
Nice amp. A service manual is available.

Denon PMA-925R Integrated Stereo Amplifier Manual | HiFi Engine

www.hifiengine.com

For starters maybe the suggestions in the thread I linked. The suggestion was to replace the bridge rectifiers and some of the op amps. One of the reasons I bought the much newer pma-600ne is that the phono section is half decent. I don't get a noticeable improvement using a CA 540p separate phone preamp on either of the Denons, and it's one of the main sources for me.
I bought the 600ne mostly out of curiosity and also because it has better digital connectivity. I've yet to read a bad review too, so I guess the curiosity bit is linked to a historical and unsubstantiated dislike of Japanese electronics. I'm a child victim of ivor tiefenbrun and the linn school of subjective analysis....(brits of a certain age will understand)

 

[Doodski]

replace the bridge rectifiers

Bridge rectifiers are amply fast and do not require high speed diodes but if you do upgrade the bridge and upgrade the smoothing caps to 18,000 micro Farad you will have slightly more dynamic peak power output. The rolling of the OP amps is generally snake oil and will not result in a notceable improvement but if you wanna try the new OP amps fly at it and have fun.

 

[ZolaIII]

Good circuit PCB design (good rooting and optimising layout) is a must and will prolong the life expectations. I am not an engineer, had my hobby time long time ago with some friends that are engineers now and working on industrial embedded grade controler SoC integration (SoM's) making PCB's and integration. Of course good quality components are at least to say desirable. If you have such they can root and make requests from partners (guys who print their PCB's) to make you new one's if old are oxidated or burnt out. Prices aren't that high but it's not really cheap either. As much as I sean that DDR guy actually gave you a good guidance on that forum.