How good are they, really? I'm looking for something to drive a woofer in a bi-amped setup, and want more power than my 2A3 SET can provide (my tweeters are about 10dB more sensitive, so I can use that amp there). My other option would be to build one of the simpler EL34 PP designs, I'm sure I can find many to choose from. Budget is a concern, I don't have too much to spend on iron. I have One Electron OPTs in the SET, and I could try to match that, but it'll probably end up being something cheaper on the new amp.
So... just curious. People on the chip amp forums rave about these amps, but I'm hoping to get an opinion from someone who's familiar with good tube amps. The gainclone is attractive because I think it'll be cheaper and simpler/quicker to build.
Thanks,
Saurav
So... just curious. People on the chip amp forums rave about these amps, but I'm hoping to get an opinion from someone who's familiar with good tube amps. The gainclone is attractive because I think it'll be cheaper and simpler/quicker to build.
Thanks,
Saurav
Hi Saurav;
Why not try an EL34 or KT88 SET to drive those woofers? You should be able to get 10 or more watts out and you'll have less investment than with a PP amp. Or you could go really wild and try your hand at a pair of Fostex FE207E in BR cabs - about 96-97dB SPL IIRC; more than plenty for a 2A3.
On gainclones:
I've built chipamps before, though mostly for headphone or subwoofer duty, so a comparison is not really fair. That said, the OPA134/OPA2134 based headphone amps tend to be a little less resolving than my better valve efforts, but at least they do not annoy. And they can be run from a single 9V battery!
Some time in the next 3 weeks I should have a small TDA2030 and/or LM4766 based chipamp ready for general purpose listening and I'll post my results and comparisons then. Frankly I'd rather be building up one of my valve projects (please don't grass on me over at the chipamp forum!
) but $$ prevents it at the moment. Anyway it should be a fun project, and illustrative of what can be done on a (VERY) small budget.
Good luck with your projects!
Morse
Why not try an EL34 or KT88 SET to drive those woofers? You should be able to get 10 or more watts out and you'll have less investment than with a PP amp. Or you could go really wild and try your hand at a pair of Fostex FE207E in BR cabs - about 96-97dB SPL IIRC; more than plenty for a 2A3.
On gainclones:
I've built chipamps before, though mostly for headphone or subwoofer duty, so a comparison is not really fair. That said, the OPA134/OPA2134 based headphone amps tend to be a little less resolving than my better valve efforts, but at least they do not annoy. And they can be run from a single 9V battery!
Some time in the next 3 weeks I should have a small TDA2030 and/or LM4766 based chipamp ready for general purpose listening and I'll post my results and comparisons then. Frankly I'd rather be building up one of my valve projects (please don't grass on me over at the chipamp forum!
) but $$ prevents it at the moment. Anyway it should be a fun project, and illustrative of what can be done on a (VERY) small budget.Good luck with your projects!
Morse
Hi Saurav;
Whoops! I'd forgotten that you had high efficiency speakers - sorry!
Anyway, if you go with an EL34 SET, you could try either Hammond 125ESE or Hammond 1627SE. If money's a concern, I personally think the answer's a no-brainer, since most everyone who's tried the 125ESE likes it - for the money. Only thing I'd warn about on cost cutting with Hammonds is to go with the 3xx series PS trafos or use a voltage dropping autotransformer to make sure that the primary of a 2xx series Hammond's not being saturated. They hum like heck when they saturate!
All the best,
Morse
Whoops! I'd forgotten that you had high efficiency speakers - sorry!
Anyway, if you go with an EL34 SET, you could try either Hammond 125ESE or Hammond 1627SE. If money's a concern, I personally think the answer's a no-brainer, since most everyone who's tried the 125ESE likes it - for the money. Only thing I'd warn about on cost cutting with Hammonds is to go with the 3xx series PS trafos or use a voltage dropping autotransformer to make sure that the primary of a 2xx series Hammond's not being saturated. They hum like heck when they saturate!
All the best,
Morse
Morse,
I had the 125ESEs on my 2A3 amp before I went to the One Electrons. I think I'll want something better than that. Maybe something in the 16xx line. That's a good tip about the PS transformer, I'll remember that. I think I have a 272something in my current amp. It's being run quite a bit under max capacity though (barely gets warm), which is probably why it doesn't hum too much.
analog_sa,
Thanks, that's useful information.
Saurav
I had the 125ESEs on my 2A3 amp before I went to the One Electrons. I think I'll want something better than that. Maybe something in the 16xx line. That's a good tip about the PS transformer, I'll remember that. I think I have a 272something in my current amp. It's being run quite a bit under max capacity though (barely gets warm), which is probably why it doesn't hum too much.
analog_sa,
Thanks, that's useful information.
Saurav
Hi Saurav;
I've got the 1627's now and they're really sweet performers. Good everywhere with no weaknesses in their audio range that I can detect with my current system. Great deal for the $$.
The easiest way I've found to rig an autotransformer for my 2A3's mains in is as part of my power filter. I'm using a 25.2VCT Radio Shack $10 special as an autoformer and it works fine - doesn't heat up too much or any of that nonsense. Only things I have to do now are to wire in a switch to allow for no drop, 6.3V drop, or 12.6V drop, and add an AC volts meter to the case of my filter. Depending on time of day and season here, I have measured 128VAC down to 113VAC - and even with my 272JX run way below Imax ratings, it hums pretty badly when the line AC is at the high end of that range....OTOH, around 119VAC it starts to quiet down, and by 115VAC it's very quiet indeed.
One last thought on the 'varying line voltage' theme is that your valve's filaments will be run hot or cold depending on how far from "normal" your AC provider allows things to slip. Without voltage regulation, you could well have diminished lifespans on some valves.
All the best,
Morse
I've got the 1627's now and they're really sweet performers. Good everywhere with no weaknesses in their audio range that I can detect with my current system. Great deal for the $$.
The easiest way I've found to rig an autotransformer for my 2A3's mains in is as part of my power filter. I'm using a 25.2VCT Radio Shack $10 special as an autoformer and it works fine - doesn't heat up too much or any of that nonsense. Only things I have to do now are to wire in a switch to allow for no drop, 6.3V drop, or 12.6V drop, and add an AC volts meter to the case of my filter. Depending on time of day and season here, I have measured 128VAC down to 113VAC - and even with my 272JX run way below Imax ratings, it hums pretty badly when the line AC is at the high end of that range....OTOH, around 119VAC it starts to quiet down, and by 115VAC it's very quiet indeed.
One last thought on the 'varying line voltage' theme is that your valve's filaments will be run hot or cold depending on how far from "normal" your AC provider allows things to slip. Without voltage regulation, you could well have diminished lifespans on some valves.
All the best,
Morse
Hi, just came across this:
http://www.vonschweikert.com/db100.html
I am working on a 40W UL PP amp for my VR-1’s. Funny enough, when I bought my VR-1’s a year ago, I was thinking of something similar: To build an active corrected and SS-amplified bas system to accompany the VR-1’s and doubling as a stand for the VR-1’s. The idea is to use the 3 x 6½ long throw bas units each box and each speaker unit powered by its own LM chip.
Cheers
http://www.vonschweikert.com/db100.html
I am working on a 40W UL PP amp for my VR-1’s. Funny enough, when I bought my VR-1’s a year ago, I was thinking of something similar: To build an active corrected and SS-amplified bas system to accompany the VR-1’s and doubling as a stand for the VR-1’s. The idea is to use the 3 x 6½ long throw bas units each box and each speaker unit powered by its own LM chip.
Cheers
Thanks. That's pretty interesting, and it's a big plus that I can buy the PCBs from him. I'm not sure if I understand one part of it though - he says the voltage gain is 1x, and he uses the tube amp's driver stage for the voltage gain? I'm not sure how I would make that work. The way I see it, the output of the linestage goes into the crossover, and then each output of the crossover goes to an amp. So my tube amp wouldn't be seeing the bass frequencies at all. I guess he has the filters after the tube amp's driver stage. I could make that work if I knew my XO points, but I want to use an outboard XO to play with this and see the effects of changing XO parameters. I'd like to try a digital XO too. So, I'm not sure if I'll be able to make this work.
Hi Saurav:
Saurav: >>>...How good are they, really? (gainclones/chipamps)...<<<
Morse: >>>...Some time in the next 3 weeks I should have a small TDA2030 ...ready for general purpose listening and I'll post my results and comparisons then...<<<
Wow! 3 weeks stretched a little, but I've got a TDA2030 up and running into a pair of RS40-1354 DIY speakers. Now, this is NOT technically a gainclone...but I think that the observations here may still be relevant.
Overall, the sound is "listenable" and nonfatiguing, but not anything to rave about...my 2A3 mops the floor with it out pretty thoroughly. In general, I'd classify it as smooth with decent bass, but limited in detail and treble extension. Moreover, there's a tendency for the midrange to become somewhat "cluttered" particularly at elevated listening levels. However, it's an easy notch above the usual "big box store" mainstream tripe - and it can be built in an afternoon once you've got practice point to point wiring chips (and the experience to get a reasonably hum-free layout; believe it or not, that was one of the biggest parts of the learning process - these chip thingies are rather touchy about hum and oscillations - more so than valves).
Even so, it's cheap thrills (cost of the whole kit and kaboodle is less than a single halfway decent OPT), and if you're looking for something a little different it might be just the ticket. Buy a few extra chips in case you trash one or two (or in case one of your buddies decides he wants one....). Just don't expect better sound than you'll get from a good DIY valve amp - because you won't get it. At least if my experiences are anything to judge by.
Later I will post a followup on this thread, when I get a chance to build a "true" gainclone. That won't be for a while though.....I've got some LM1875's in with a general order of parts, and it won't be 'till after I get some of those to play with that a GC can take shape. Frankly, if $$ permits, I really want to get one of my stalled valve projects off the ground! The spirit is willing, but the wallet is weak.....
Ja mata,
Morse
Saurav: >>>...How good are they, really? (gainclones/chipamps)...<<<
Morse: >>>...Some time in the next 3 weeks I should have a small TDA2030 ...ready for general purpose listening and I'll post my results and comparisons then...<<<
Wow! 3 weeks stretched a little, but I've got a TDA2030 up and running into a pair of RS40-1354 DIY speakers. Now, this is NOT technically a gainclone...but I think that the observations here may still be relevant.
Overall, the sound is "listenable" and nonfatiguing, but not anything to rave about...my 2A3 mops the floor with it out pretty thoroughly. In general, I'd classify it as smooth with decent bass, but limited in detail and treble extension. Moreover, there's a tendency for the midrange to become somewhat "cluttered" particularly at elevated listening levels. However, it's an easy notch above the usual "big box store" mainstream tripe - and it can be built in an afternoon once you've got practice point to point wiring chips (and the experience to get a reasonably hum-free layout; believe it or not, that was one of the biggest parts of the learning process - these chip thingies are rather touchy about hum and oscillations - more so than valves).
Even so, it's cheap thrills (cost of the whole kit and kaboodle is less than a single halfway decent OPT), and if you're looking for something a little different it might be just the ticket. Buy a few extra chips in case you trash one or two (or in case one of your buddies decides he wants one....). Just don't expect better sound than you'll get from a good DIY valve amp - because you won't get it. At least if my experiences are anything to judge by.
Later I will post a followup on this thread, when I get a chance to build a "true" gainclone. That won't be for a while though.....I've got some LM1875's in with a general order of parts, and it won't be 'till after I get some of those to play with that a GC can take shape. Frankly, if $$ permits, I really want to get one of my stalled valve projects off the ground! The spirit is willing, but the wallet is weak.....
Ja mata,
Morse
I know I'm jumping into this thread late, but I thought I would put a good word in for the gainclones. While the gainclone I built wasn't as nice as my normal tube amp (6AS7 OTLs) they were better than several budget tube amps I have built in the past. If the budget is tight they are definitely worth trying out, as in my experience you would be very hard pressed to beat a gainclone with an equally priced tube amp.
Doug
Doug
Hi Doug;
Sorry, I didn't mean to make it sound like I was belittling the GC - particularly since I technically did not build one! That will be a forthcoming project though....
>>>...If the budget is tight they are definitely worth trying out...<<<
Absolutely! Any chance to make solder fumes is taken over here, and it certainly has been a fun little project. And, for those on a really tight budget, or looking for an "expendable" amp (office, dorm room, etc), they certainly bear looking into.
>>>...as in my experience you would be very hard pressed to beat a gainclone with an equally priced tube amp...<<<
Yep, I don't think I could have built a valve amp on the under $45USD (including tax!) that it cost me to put together this little chipamp - OTOH, my 6BM8 Gnat definitely outdoes it in midrange and treble "rightness", although admittedly the TDA2030A has better bass (I attribute that to the $9 OPT's!).
All the best!
Ja mata,
Morse
Sorry, I didn't mean to make it sound like I was belittling the GC - particularly since I technically did not build one!
That will be a forthcoming project though....>>>...If the budget is tight they are definitely worth trying out...<<<
Absolutely! Any chance to make solder fumes is taken over here, and it certainly has been a fun little project. And, for those on a really tight budget, or looking for an "expendable" amp (office, dorm room, etc), they certainly bear looking into.
>>>...as in my experience you would be very hard pressed to beat a gainclone with an equally priced tube amp...<<<
Yep, I don't think I could have built a valve amp on the under $45USD (including tax!) that it cost me to put together this little chipamp - OTOH, my 6BM8 Gnat definitely outdoes it in midrange and treble "rightness", although admittedly the TDA2030A has better bass (I attribute that to the $9 OPT's!).
All the best!
Ja mata,
Morse
Hi Saurav;
Here's an update on the TDA2030A chipamp.
The "audio mud" in the midrange cleared somewhat after about 24 hours of burnin time. A much larger improvement in midrange clarity and upper midrange "snap" was made by snubbing the FR305 diodes that I used for my rectifier bridge (usually I snub all ss diodes as a matter of course, but as an experiment I left these "fast recovery" diodes unsnubbed at first). Anyway, the snubbing caps have cleared the midrange mud to the point that it's gone from a fun toy to a moderately serious piece of gear (no, it doesn't have the midrange "magic" of a 2A3 or the "sweetness" of a 6BM8 or 6V6; but for ss kit it's really rather charming in it's fashion) - particularly when the low $$ aspect is taken into account. I'd classify it as being serious enough that I could see myself using one as a standin piece of gear for when the 2A3 is down for upgrades.
DEFINITELY snub your diodes on chipamps - they really do seem more sensitive to the effects of these sorts of things as are valves. And, though I will admit to not doing the experiment on this particular amp, given the improvements I've heard in valve amps with the fitting of a UL Listed "X" cap to the AC mains as an interference suppressor, I would also go with that from the first - I did.
If you're going to build one for a dedicated subwoofer driver, you ought to try your hand at building one as a general purpose amp first in my opinion. Then experiment around a little with how much capacitance you want for the PS filter, get your layout so that oscillation and hum are not issues, etc. Particularly since it sounds like a long range project for you, you have time (and the LM1875's are about $2.5 each at Digikey, so you won't go broke experimenting!).
Good luck and all the best!
Ja mata,
Morse
Here's an update on the TDA2030A chipamp.
The "audio mud" in the midrange cleared somewhat after about 24 hours of burnin time. A much larger improvement in midrange clarity and upper midrange "snap" was made by snubbing the FR305 diodes that I used for my rectifier bridge (usually I snub all ss diodes as a matter of course, but as an experiment I left these "fast recovery" diodes unsnubbed at first). Anyway, the snubbing caps have cleared the midrange mud to the point that it's gone from a fun toy to a moderately serious piece of gear (no, it doesn't have the midrange "magic" of a 2A3 or the "sweetness" of a 6BM8 or 6V6; but for ss kit it's really rather charming in it's fashion) - particularly when the low $$ aspect is taken into account. I'd classify it as being serious enough that I could see myself using one as a standin piece of gear for when the 2A3 is down for upgrades.
DEFINITELY snub your diodes on chipamps - they really do seem more sensitive to the effects of these sorts of things as are valves. And, though I will admit to not doing the experiment on this particular amp, given the improvements I've heard in valve amps with the fitting of a UL Listed "X" cap to the AC mains as an interference suppressor, I would also go with that from the first - I did.
If you're going to build one for a dedicated subwoofer driver, you ought to try your hand at building one as a general purpose amp first in my opinion. Then experiment around a little with how much capacitance you want for the PS filter, get your layout so that oscillation and hum are not issues, etc. Particularly since it sounds like a long range project for you, you have time (and the LM1875's are about $2.5 each at Digikey, so you won't go broke experimenting!).
Good luck and all the best!
Ja mata,
Morse
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.