chip amps: Almost everything you ever wanted to know

[rhing]

Rich-

The SA-50 just arrived and I've not listened carefully fo any extended time. These almost Medicare eligible ears think they both sound very good.

That doesn't mean there isn't a sound quality difference or that they won't get tweaked.

Please share your results. I'll keep haunting DIY forums for possible tweaks.

What speakers are you using with these amplifiers?

[DizRotus]

Rich-

The SA-50 just arrived and I've not listened carefully fo any extended time. These almost Medicare eligible ears think they both sound very good.

That doesn't mean there isn't a sound quality difference or that they won't get tweaked.

Please share your results. I'll keep haunting DIY forums for possible tweaks.

What speakers are you using with these amplifiers?

A pair of these,as described back at page 1.

I've also used them on La Scalas briefly, but the comparisons are made using the single drivers.

[DizRotus]

Mark,

My objective is to ward off creeping (if not galloping) senility and to justify the purchase of a router. I also enjoy amazing my friends with the sound from those Rat Shack speakers and ancient Dynaco tube gear or chip amps. In short, it's a hobby.

If by "main rig" you mean what do I listen to most often, then it's a pair of Klipsch ProMedia 2.1 while toiling at the computer. Next would be a pair of DIY LS3/5As with a pair of DIY KEF B-139 transmission line subs, all made decades ago when I dismantled a pair of DIY Webb speakers (see below) built from an article in the late lamented "The Audio Amateur" magazine. The KEF based system comprises my modest HT and provides the soundtrack to Detroit Tigers games, DVDs and the like.

As to the relatively rare opportunity to sit and just enjoy music, it was using the rear horns until they were recently dismantled to build the second pair of the now preferred BR single drivers. Now I use a pair of the single drivers, soon to augmented by a QD-1, under Dave Mallette's bad influence, and a second pair of single drivers. While outside, I listen to the "iPod dock" on steroids described elsewhere.

After selling Cornwalls to Ms. Valerie, giving a Heresy pair to my son and presenting La Scalas to the high school, I'm now without any plywood Klipsch.

I recall you once describing a period when you were content to listen to a clock radio (probably KLH 1 or Tivoli) if the music, recording and performance were good. whether I'm mistaken about attributing that to you, it still sums up my feelings. I'd rather listen to a great performance, well recorded on a mediocre system, than a crummy recording of a poor performance on a state of the art system. Nonetheless, I enjoy tinkering and getting the most out of the least.

Thanks for inquiring.

[DizRotus]

It was in "The Audio Amateur 1/1975, not its spin-off "SpeakerBuilder Magazine" (also gone and missed), pages 1 -3 of the article are attached.

[DizRotus]

Pages 4 - 6 are attached.

[DizRotus]

Pages 7 - 9 are attached.

All of the drivers and crossover components for the Webb and the LS3/5As were purchased from Falcon Acoustics in the UK. I think it' may be OOB now also.

[erik2A3]

I used to really enjoy Speaker Builder and Glass Audio. Fun days!

Thanks for sharing your projects!

[rhing]

Pages 7 - 9 are attached.

All of the drivers and crossover components for the Webb and the LS3/5As were purchased from Falcon Acoustics in the UK. I think it' may be OOB now also.

Jerry Bloomfield of Falcon Acoustics still runs a fine operation. I helped my non-DIY friend recap his KEF Reference 101 monitors using tested and matched Alcap electrolytic caps (same as OEM caps) from Falcon Acoustics, and the results were fantastic. With his revamped Conrad-Johnson MV75-A1 75 watt amplifier, my friend's system sounds great.

I do like the British speakers, but my preference is for the Klipsch Heritage series speakers with upgraded crossovers and internal wiring. With T-amps and tube amps, they just sound magical to me.

[DizRotus]

Quote

Quote

Pages 7 - 9 are attached.

All of the drivers and crossover components for the Webb and the LS3/5As were purchased from Falcon Acoustics in the UK. I think it' may be OOB now also.

Jerry Bloomfield of Falcon Acoustics still runs a fine operation. I helped my non-DIY friend recap his KEF Reference 101 monitors using tested and matched Alcap electrolytic caps (same as OEM caps) from Falcon Acoustics, and the results were fantastic. With his revamped Conrad-Johnson MV75-A1 75 watt amplifier, my friend's system sounds great.

I do like the British speakers, but my preference is for the Klipsch Heritage series speakers with upgraded crossovers and internal wiring. With T-amps and tube amps, they just sound magical to me.

Richard-

Glad to hear that Falcon Acoustics is still in business.

I agree about the sound of refreshed Klipsch Heritage (plywood and T-35s) or the equivalent (or better) horn-loaded speakers compared to British, such as KEF. My KEF based speakers sound good, but Klipsch sound alive by comparison, especially when played loud. My BBC LS3/5A DIY with KEF B-139 TL subs sound fine at reasonable levels, but they're very inefficient (which PWK equated to distortion) demanding a lot of power to play loudly.

One is much more likely to walk down a street and come upon an open door expecting to hear a live band, and then be surprised to see La Scalas or upside-down decorator Khorns at full boil than to find KEF, Warfdale or even Tannoy sounding like a live band.

[seti]

I tried two tripaths. In the short term they are fun but in the long run you start to want to get rid of them. I killed mine trying to modify them to get better sound. RIP

[CECAA850]

I tried two tripaths. In the short term they are fun but in the long run you start to want to get rid of them. I killed mine trying to modify them to get better sound. RIP

Are the new TI chips or B&O chips any improvement in this category of amp? I too only had the Tripath years ago. I would imagine something has changed in 5 years, no?

Mark, if you ever want one to hot rod and play with, I'll send you my Indeed amp and pay for all the parts and shipping both ways. I love what you did with my Crown.

Carl

[CECAA850]

Mark, if you ever want one to hot rod and play with, I'll send you my Indeed amp and pay for all the parts and shipping both ways. I love what you did with my Crown.

Carl

Dude! You have my Crown D45? Really? Get outta here!

Which model exactly of the "Indeed" amp do you have? Yes, I have a couple ideas about these things, but right now I am knee deep in a speaker restoration. But listen - let's talk later about this idea.

I've had the "Duke" for several years. I think Dean had it, then joesporster. I got it from him. It's found a permanent home. You can see what it's paired with in my sig.

I don't know the model # off hand on the Indeed. I'll check tonight when I get home.

[CECAA850]

I've had the "Duke" for several years. I think Dean had it, then joesporster. I got it from him. It's found a permanent home. You can see what it's paired with in my sig.

Cool. I assumed "The Duke" was long gone to the Ebay abyss of old HiFi gear! I fell in love with the sound of that amp. It was really sweet. I am happy to hear it is in a nice home. I think a guy or two here got the instructions for making it, and maybe there are some "Sons of Duke" around? If I do get my whole test bench up again, I'd be tempted to make another one for my system. There's new BurrBrown OpAmps now that are even better than what went into the first one.

I've never had it paired with any other pre-amp than the Anthem it's with now but that combo is really nice. I'll keep that amp till it breaks.

[CECAA850]

Which model exactly of the "Indeed" amp do you have?

It's the Tripath TA2021. 25w x 2.

[Marvel]

I think a guy or two here got the instructions for making it...

You sent a set of instructions to me but I'm knee deep in debt and not getting very far with projects that take much money. I'll also need to dig those instructions out and make sure they are safe before a hard drive dies or I just can't find them.

Bruce

[CECAA850]

This is the new and improved amp. Not sure if mine has these "improvements" or not. I realize this isn't a schematic however. I like the little amp but haven't given it a proper source. I mostly feed it directly from my I pod. The 25 wpc rating is at 4 ohms, more like 18 wpc at 8 ohms. The most efficient speakers I've used it on are my Forte ii's. It's very clean at lower volumes but the bass lags behind the mids and treble once you get past midway on the volume knob. I'd like to hear it on a couple other pre amps I have but haven't gotten around to plugging it in. I'd guess it'd sound good with my Lascalas and Anthem pre.

[Marvel]

Do you already have the D45?

No, that would be the problem... Too many things are taking precedence right now. Maybe some day, you know. THe other amp I was looking at was the Parasound Z-amp. I would like to try one some time as well.

Bruce

[seti]

I tried two tripaths. In the short term they are fun but in the long run you start to want to get rid of them. I killed mine trying to modify them to get better sound. RIP

Are the new TI chips or B&O chips any improvement in this category of amp? I too only had the Tripath years ago. I would imagine something has changed in 5 years, no?

I found them interesting but they didn't make it long term for me. I don't know if they are any better now or not. Once I switched back to tube amps I never wanted to go back. I would listen to someone elses before buying another chip amp though.

[rhing]

I've found with using my SMSL SA-S1 with my Audio Research PH5 tube phono stage, I get a lot of the magic of tube audio. It still doesn't match the sound when I go with all tubes, but it does sound very nice with a bit of the holographic quality that tube amps provide. I listened to other Class D amps based on B&O's Ice Power, and Hypex amp modules, and they were okay, but not really as involving as Tripath-based Class D amps I've heard. One of the better Class D amps I've heard was a Lab Gruppem pro audio amplifier based on their Class TD technology. I have no idea what chip technology Lab Gruppen amps are based on, but it had similar sound qualities of Tripath Class D amps--clear sound and nice harmonic content without the high frequency artifacts that other Class D amps have. It's too bad Lab Gruppen doesn't make consumer audio amplifiers.

Edited November 7, 2013 by rhing

[rhing]

At the recommendation of some people on the diyAudio.com Class D amplifier forums, I decided to purchase a TDA7297 Class AB chip amp from an auction seller, Homemart.USA. The amp only cost $4.99 plus $1.00 shipping from Hong Kong. Several people claimed that this amp sounds better than the SMSL SA-S1 TA2020 Tripath Class D (i.e., Class T) amp. I've wasted $6 on bad lunches before, so I figured what could I lose.

Within a week, the amp module came in a padded envelope from Hong Kong. It was wrapped in Saran Wrap and bubble wrap. The amp has a 2" x 2" footprint. The heat sink, which is the largest component on the printed circuit board is a bit less than 2" high. This amp is tiny. I wired it up in a makeshift test bed with 5-way binding posts and good quality RCA connectors. I hooked up my Klipsch Forte IIs, my Sony SACD/CD player and powered up the amp with the same modified power supply I used with my SMSL T-amp. I've been listening to music the last two evenings using this tiny amp, and I am amazed that this amp really does sound better than the SMSL amp. It digs deeper in the bass and sounds clearer than the SMSL amp. The tonality is balanced, the timbral detail is nice, and the amp has plenty of headroom despite its low power spec. I've listened to rock, classical and jazz, and I am impressed with the size of the soundstage and well defined imaging.

The funny thing is the data sheet from STM, the chip's manufacturer, states that applications for this chip include televisions and portable audio.

Edited November 7, 2013 by rhing