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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 02:52 
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Joined: 06 Jun 2008, 18:23
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Geek: a little off thread but have you seen any other transformer only amps like my Intermezzo?

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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 03:49 
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Joined: 08 Aug 2009, 03:11
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Hi Mark,

I am an old geek with brainfarts.... link to Intermezzo? :blush:

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* Ratings are for transistors - tubes have guidelines*
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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 04:21 
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http://www.diyaudioprojects.com/Forum/viewtopic.php?f=9&t=4289&start=10#p35100

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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 14:52 
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Thanks!

Yes, I have - extremely high powered commercial amps (1KW+) from GEC and Telefunken as well as transmitter modulators (to 250KW audio power) use a no-nonsense transformer in and transformer out approach like that :D

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* Ratings are for transistors - tubes have guidelines*
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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 19:01 
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Thanks. What about something for the home? Any schematics?

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Projects: "Tutu" - 150W Tripath T3 monoblock | "Silver Supreme" - 6L6GC-12AT7 SE UL power amp | "retro-4040" - 40W Chip amp LM3876T
Website: retro-thermionic


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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 20:46 
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Joined: 28 May 2008, 21:53
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Location: Winnipeg, CANADA
mwhouston wrote:
In the latest Stereophile two tube power amps are reviewed and tested. The reviewer did find some audible faults with the amps, particularly the lower power one (made in America and designed in Korea) but if you look at the test results they are horrific. Distortion level were not only high but the worse distortion patterns I have ever seen. John comment on the poor test result of the amp. I think John could have or should have been more critical.

Hi all - sorry for jumping in late. I actually started subscribing to stereophile this winter mainly because it is quite inexpensive delivered right to your door - even in Canada. However, for some of the reasons already mentioned by others, the quality of the stereophile reviews is rather poor so I normally just gloss them over rather quickly.

Looking at the May issue the test results of the $7295 Raven Audio Spirit 300B are as Mark noted - atrocious! Into a simple 8 ohm load, the push-pull 300B amp is +1dB / -6dB across 20Hz to 20kHz and even worse for tougher loads. The 10kHz square wave looks like an almost perfect sine wave. Remember, this is a $7k push-pull amp, so really quite brutal performance.

The only thing worse than the performance of the amp was the stereophile review. They mention the persistent left channel hum. The measurement comments suggest using 16 ohm speaker on the 4 ohm tap for better linearity, but acknowledges a roll-off of the top octave regardless. So after all that and a whole lot more nonsense, guess how stereophile chooses to capture the review on the front page of their magazine ...

"TERRIFIC TUBE AMPS"
"Raven's Spirit & VTL's Sigfried"

How's that for review entertainment? I guess that explains why they practically give the magazine away.

Cheers

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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 21:18 
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In reply to Gio's comments: bad testing amps will not stop me reading stereophile. For every bad test there are ten good tests. Let's face it not every piece of audio gear is going to be perfect or test well. I guess what got up my nose was this moderately expensive amp tested so poorly and the manufacturer had the audacity to release it as is. If I can produce a DIY tube amp which test reasonably well and sounds good surely a company can do better. Maybe the hum is there to let you know the amp is on. Lol.

Thank God JA calls it as he sees it. But oddly over the past few months there has been a spate of gear which has been poorly made and tested badly. Is it a virus, if so what is the cure?

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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 21:52 
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Hi Mark - certainly they are not to blame for a poor testing amp, but calling it "terrific" is at the very least, misleading. (see I can be polite too!) Plenty of nice photos in the magazine, but I like the magazine more for it's entertainment value as it is not a good reference source.

I'd like to see stereophile devote some articles to the reading and understanding the test results. I think the more people understand the measurements, the better.

Cheers

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[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


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 Post subject: Re: hifi or mifi
PostPosted: 11 May 2014, 22:37 
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Joined: 08 Aug 2009, 03:11
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mwhouston wrote:
Thanks. What about something for the home? Any schematics?


Sure!

Thee's a lot of IST driven 300B schematics floating about (the Japanese love them) as well as 845's and 811's. The user "Choky" at diyAudio is an iron fanatic :D

No links off the top of my head right now, though...

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* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
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 Post subject: Re: hifi or mifi
PostPosted: 13 Apr 2016, 13:01 
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Joined: 01 Jun 2013, 09:05
Posts: 555
its interesting to go to hifi conventions,

I think its a must do for anyone interested in audio reproduction. However you must be prepared for a shock that you might not like HIFI.
Also just how bad some equipment can sound and the different opinions of others things they like and dislike.
I have said this before, I think some HIFI is like perfume the bottle looks great!
The trouble with HIFI is its all about opinions and what one person wants another hates.
During a HIFI show some time ago I remember being un-impressed with a lot of the equipment and walking into a room with some refurbished PYE amps and instantly wanting one :bawling: the reason was it was relaxing like a breath of fresh air after listening to the hundreds of rooms of equipment.

One of the most impressive systems I have listened to some time ago was not tube (shock horror) using a counterpoint DAC with Krell amplification and magnepan speakers running a sub woofer that made a church organ materialise in the room all quite spectacular. I had a long listen to Ongaku and the Gaku-on etc..all very interesting but you know when you get that ermm moment.. :D
I'm not convinced these days something seems to be missing.
Personally I like small equipment its not a case of MIDFI etc its the divide between practical and sound. With formats changing so fast its hard to know where to begin. Years ago I got disillusioned with HIFI and scrapped all of it and bought a reasonably good MIDFI. It ran for a few years and got ditched again :D I have watched people I know change expensive equipment like buying sweets. Then they listen to something else and their equipment suddenly becomes rubbish again. I believe the reason is that not much equipment can play different types of music well and when people change what they listen to the equipment can't cope. So the MIDFI argument may have some merit if it can play most music reasonably well but nothing fantastic.

Regards
M. Gregg

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