The 90s were a dark time for audio equipment, literally and figuratively. Essentially the only redeeming quality from the decade of nondescript black plastic boxes was the low cost. Compared to the audio equipment of the 60s, largely produced in high-end enclosures with highly desirable tube amplifiers, the 90s did not offer much when it came to hi-fi stereo sound. However, those cheap black boxes from the 90s turn out to be surprisingly perfect for project enclosures for other amplifier builds, such as this 60s-era tube amp recreation.
This mesh of the best of two distinct decades comes from [Alvenh] and begins by preparing the old enclosure for its new purpose. This means a lot of work fabricating a custom metal face plate for the new amplifier and significantly modifying the remaining case. After the box is complete, the amplifier build began. It uses a tube-based preamp and a solid-state power amplifier since [Alvenh]’s experience suggested that the warm tube sound was generated mostly in the preamp. This means that his design is a hybrid but still preserves the essential qualities of a full tube build.
The build also includes a radio module that has the ability to cover the 2m and 70cm bands popular in ham radio. This module also has been found to have much better audio quality than the standard AM/FM receiver typically used in projects like this. With the radio module added to the custom enclosure, as well as a phono amp and a power supply, [Alvenh] has an excellent audio amplifier in an inexpensive case which preserves the tube sound from the true hi-fi eras of decades past.
Uncomfortable truth: Hi-fi is all about the watts you can get before clipping, nothing else really matters
What! You mean I really don’t need a 0 gauge power cord between my amp and the power outlet on the wall!
Say it’s not so!
Cables will make a difference in sound quality, but only up to a certain point. Double blind tests have demonstrated that listeners were not able to distinguish $10,000+ speaker cables from ordinary $30 monster cables.
Yep, any theoretical degradation supposedly has to do with a reduction of the speaker’s damping factor due to cable resistance. For the short runs in a common home installation this isn’t a significant factor.
In another blind test done by an audio magazine many years ago they modified a high quality amp so they could dial in various harmonic and intermodulation distortion (IMD) for a group of “golden ears.” For harmonic distortion it was in the integer percentage range before they detected it, but for IMD it was in the fractional percentage range. However, they proved what they had suspected, that the harmonic and IMD “wars” going on between manufacturers at the time were stupid because both were at least an order of magnitude above any amp at the time from any recognized quality manufacturers.
Due to cable IMPEDANCE.
That’s to be expected because the human brain is used to hearing harmonics and will infer the so-called “missing fundamental” from its multiples which is a trick used to boost the apparent bass output of tiny loudspeakers, whereas IMD produces spurious frequencies which are not harmonic to any of the real signal content.
However, the real show is to put an expensive speaker tower and its cheap consumer model side-by-side, simply EQ the cheaper speaker to sound “identical”, and then do an ABX blind test. The golden ears are lucky to tell a difference there either. Sure, they may have a slightly different “tone” to the sound, but which is better?
I use solid core ring main wiring cable for speakers, the kind of stuff that electricians use when their wiring plug sockets into the mains. It actually sounds really good. but when it comes to interconnect I found Linn black analogue interconnect takes a lot of beating.
Not unless it’s gold plated unobtainium with a unicorn horn plug!
Some cheap audio hardware has audible noise and distortion, too. Maybe that goes away once you spend a little more money?
HiFi is all about whether your amp can respond quickly enough to incoming signals and produce an accurate output, and do it without adding noise. Clipping just means you’re trying to drive the circuit’s output beyond the voltage rails. How loud you can get before clipping has NOTHING to do with fidelity.
I’d argue it’s much more than just clipping. There are plenty of ways the frequency spectrum and waveform (if you care about phase, which is debatable at audio) can be changed by amplification processes and chains. But, no, you don’t need tubes or super-fancy components to do a good job. Though, if you are a builder and designer, you do need some dependable test equipment.
In other words, gobs of headroom. Make sure you allow for headroom within stages as well.
Baloney.plain and simple. Hi end audio aims to re create a listening experience for the owner. Watts mean Nothing just as a 40 HP VW can do 60mph,So can a 300 HP vintage Corvette. Just different experience.
You have never heard a great system. A decent system is obviously better even at low sound levels.
You dont know what your talking about.
correction, hifi is about where below 150 Hz your -6 db point is.
“The 90s were a dark time for audio equipment”
This is like being depressed because you polished your car to optical perfection and then you could not get it any better.
Nah, the 90s truly were bad. It was the time when the class of decent, separate component hifi systems were replaced by all in one mini/midi sets that were generally intensely mediocre. The crap has always been there, but in the 90s the crap became more popular than the good stuff.
Some brands completely stopped making proper hifi stuff. Take Philips, one of the biggest hifi manufacturers in Europe. At the end of the 90s, they barely had any separate components left.
Akai, the one that made really good amps and tape decks, disappeared completely. As did RFT and Tesla, two great eastern bloc electronics manufacturers.
Don’t get me wrong – you could still get some good stuff, but in the mainstream, investing in a hifi system became rare and people massively bought into those sad all in one systems. Walking into the local electronics store wasn’t always an option anymore, for the separate components you had to find a specialized hifi store. At least in the Netherlands.
You have the wrong decade. A decade later thats true. In the 90s there were large #s of good stereo hi-fi systems from Technics, Harmon Kardon, Sony, and a pile of others. They were still being sold in department stores and so many of the specialty electronics stores that have since shuttered. I still own some to this day.
I agree. As a RadioShack manager in the early 00’s, I watched the transition from components to AiO units. By 2010, only a single 4 channel Sherwood unit remained.
I also agree and opine it was the introduction of the first iPod that drove the demise. People wasn’t to carry all their music and listen to it on portable players using crap earbuds. Slow sampling rates, lossy encoding, etc, all to fit more music on the portable unit meant the average person no long aimed for hi fidelity in a proper room with good speakers.
Hi Fi tube sound ? Next I’ll hear how 8 tracks were superior to CDs.
I agree, the 90’s weren’t the dark ages!
There is no ‘good’ from the 60s as far as sound is concerned – yes, all those glowing values looked good, but the music certainly didn’t sound good. When those new transistor based amps came out, yes, they didn’t sound too good. But by they got better pretty quickly, and it’s now been over 40 years since I’ve wanted to listen to a tube amp…
Especially since the 1960s was the heyday of the 5 transistor portable radio.
> I still own some to this day
Same! My Denon and Cambridge gear from the 90s is still going strong. I’ve had to service them less than my 80s McIntosh gear, and I’ve recapped and replaced the power supplies in my early-2000’s Meridian gear twice. The Denon gear — comparatively speaking — is “Mid-Fi”, but it’s still strong to this day. When people stopped making stuff in Japan? That’s when it went downhill.
Most of the makes you quote are barely hifi! Deltec….quad ….linn…arcam…SME that’s hifi
If you think ’90 were so bad look at all these people listening music on smartphones or mono bt speakers at best. Also ’90 not the cheapest but cheap micro systems had pretty good amplifiers and speakers compared to today stuff from manufacturers such as Panasonic, Philips, Grundig etc
“Nah, the 90s truly were bad.”
Due to the switch from high quality, expensive hardware made in Japan for the relatively few to cheap integrated systems made in China for the masses.
In the 2020’s, people listen to music on TV sound bars, phones, bluetooth boom boxes, and smart speakers. I expect All American 5 AM radios to come back.
Hi, Alvenh here. Thanks for posting. I’m the one who built this hi-fi set and it was a fun project. However, I would just like to point out that this unit is strictly an audio amplifier and has no radio tuner (the radio receiver is a separate project). The amp, however, does use a couple of VHF/UHF RF transistors but they handle audio signals in the driver stage only because they happen to have good sound; there should be no RF signals anywhere in the set. The amp also has a MONO AUX input for audio from police scanners and other devices with mono audio output, which feeds the mono audio into both left and right channels. Because the MONO AUX input is rarely used, I might rewire it into a STEREO AUX so I can make use of my old reel-to-reel tape machine.
For those curious, the reference to the 2M capable “radio module” is
“Though rarely (if ever) used in audio applications, I have found that the 2N3866 is an excellent performer with a smooth warm sound when used in small signal (i.e. preamp and driver) stages”
Which he uses in the preamp module circuit instead of the supplied small signal transistor.
Thank you for pointing this out. Radio modules are part of another project and have nothing to do with this audio amplifier.
Rarely used for a long list of good reasons, one of which it has far too much gain decades away from audio freqs.
Assuming no parasitic oscillation, a higher f_T should, IIUC, reduce intermod and distortion, i.e. give a less “warm” sound
There’s not much “tube sound” in this design. The preamp has lots of negative feedback and won’t deliver the “warm” distortion, the transistorized power stage will domainate the overall listening experience. If one can really hear the tubes, then they are worn out and should be replaced.
Look is great! It deserves a far better amp / preamp design. There are great transistor and tube designs, and regarding to the tubes, you should not look at “tube sound”, which is just like instagram filters mimicking argentic process limitations.
Personally, for playback, I’d rather have accurate replication of the sound, and not add “color” to it. For guitar, bass, vocals, etc, live performance or in the stuido it’s fine. It how they want you to hear it.
Sound recordings have always been optimized for the average reproduction gear of the target audience. Most of the older stuff just sounds awful on a modern stereo. Better put that shellac on a 1940’s radiogram and you can hear Ella shine and Duke smile.
Nice retro design!
I’m suspicious about the transformer; Should it be rotated 90deg to prevent hum induction?
No, just put a large enough brick on top of the amp.
Nah, if he had a Choke or a Output Transformer then I would worry about placement.
Hum is part of getting that valve experience! It’s like crackle and pop with vinyl records.
Why you’d want to go back to either is beyond me – apart from values looking ‘cool’.
I have a different opinion. Tubes and vinyls were not about hums and crackles. For the simple minded perhaps, but not the audiophiles or hi-fi enthusiasts.
My father, fir example, was using a record player with capacitive touch buttons and a moving-coil head and kept his vinyls carefully storred in their paper sleeves all the time. He also checked for dust before playing. He had a 70s hifi system from Matsushita, along with proper speaker boxes with ribbon tweeters and Sennheiser HD 424 headphones.
The same misunderstanding halpens with “8-bit music”.
It’s not about low-fi. People into chip tunes don’t watch music videos in 240p, either.
Synthesizer music that uses Yamaha OPL3, for example, is being sampled at 49KHz. Likewise, NES and other old video game consoles use a high sampling rate and very good filtering.
I just spent 2 years replacing my stereo I had for 28 years and purchased in the early 90s. I spent a lot more (inflation adjusted). I replaced my old denon receiver with separates (marantz pre/pro and 2 outlaw audio amps, and my panasonic cd player with a marantz cd network player), and it is just as ugly as my old system. However, it sounds a lot better. There is always a premium if you want good aesthetics in addition to good sound, and that was as true in the 90s as it is today. For those of us on tight budgets, the first thing we forgo is design, and instead focus on getting the best sound/build quality for our money. I’d love to have a luxman, mcintosh, pass labs, etc, which offer great sound & design, but never going to happen.
“warm tube sound”?? Consider that any time two amplifiers sound different, _at least one of them_ is distorting the signal in some way.
Second order harmonic distortion for tubes.
There’s another phenomenon. Electron tubes go softly into saturation. Transistors don’t feature that. Not even field-effect transistors, the tube wannabes. They quickly distort, then get blocked due to overload.
The worst thing of the 1990s was the start of the ‘loudness war’. Commercial recordings began to be recorded with ‘loudness’ as the main objective, and FM broadcasting began to add compression on top of it. Listen to something like Depeche Mode’s “Playing the Angel” – it’s recorded so loud there is actual digital clipping all over the place.
On top of the loudness war, media monopolization killed the desire to improve or even listen to FM radio. No point in caring about SNR, channel separation, or image rejection if everything is compressed to hell and all sounds the same.
HIFI listening seems to have shifted to home theater. You’ll still find dynamic range and preserved transients in movie soundtracks, and audiophile snobbery aside, a $500 7.1 home theater integrated amp provides enough clean watts for just about any home listening situation.
This is true. I have a (relatively) low-end Yamaha receiver (483) connected to Polk S50/S55’s and S30 center, and 10″ sub in a HT configuration (since it’s primarily used for that function) and it far surpasses the quality of anything I purchased in the 90s and early 2000s.
I’d say it stands up to — and compares favorably with — the HK630 / Pioneer CS-99A system of my father’s that I grew up with; despite the fact that he owned a record store at the time he purchased those components, and had access to all the high-consumer-end stuff.
The 1990s were bad because:
Clear Channel began destroying FM broadcasting with homogenization via monopoly.
The ‘loudness war’ destroyed the quality of recorded music.
Can you even buy a decent 2-channel integrated receiver and a pair of floorstanding speakers which don’t require a subwoofer at a physical retailer anymore?
THAT IS A GOOD, QUESTION,,,, IF, YOU DON’T MIND SPENDING,
A, LOT OF COIN,,, REA, FRESH, A, MARANTZ AND OR, A ROTEL, AND A PAIR, OF CERWIN VEGA 3WAY,FLOOR, SPEAKER, S,,, AND THAT IS THAT
Here here, one is likely to encounter high def sound only in a bluray disc of a movie. Everywhere else is gone, the pink noise of reality has been raised to the white noise contour.
in my opinion volume must be bigest knob
everything is ok
Take a look at the simplicity of a tube wiring diagram. Check the physical differences between a power tube and a transistor. I’ve had some magical sonic experiences with tube equipment, the keyword might be dynamic range. I swear I never heard anything like the old Radionette radio cabinet SW sweeps and blips from my childhood tweaking those knobs was like a gateway to another dimension. Another time I woke up to an old Wurlitzer playing Eubie Blake’s ‘Memories of You’ – those horns literally blew my mind. Compare the grey mylar of an LCD television to the glow of CRT screens. Accuracy isn’t everything, sometimes old tech is just … more beautiful ❤️
YOU ARE, CORRECT, THE GLOW, OF A CRT, EARLY, COULR 📺, TV, AND BLACK, AND, WHITE , TV’S,, I, HAVE A, COLLECTION AND THE SOUND, QUALITY, ADMIRAL LAT, 40/S,, PULLING, THE SPEAKER, OUT OF THE LOWER, BOX, HAS, A, SCREW AND. NUT, TO, ADJUST THE, SPEAKERS, TENSION,,, JUST,,, AMAZING, QUALITY AND SOUND,,,…
I don’t know. 60s gear is before my time. 90s stuff is everything bad the article says it is. But what about the 1970s? I thought that was more the high point of hi-fi.