| G |
Hi all'
I was wondering if a PP 2A3 amp would be able to drive a set of Wharfedale MFM-1's (90-91 dB 1watt/1meter) satifactorily? The thing that I'm concerned about is bass response. The amp will put out about 10 watts before clipping into an 8 ohm load. I listen to jazz and old rock & Roll (some new stuff). Opinions?
G |
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| Joel |
Well, do the math:
90dB........... 1W
93dB........... 2W
96dB........... 4W
99dB........... 8W
100dB......... 10W
Last time I checked, 100dB is LOUD. You won't want to be in the room. 120dB is getting near permanant hearing damage.
Joel |
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| G |
Your right Joel. 100 dB is LOUD. Thanks for the opinion.
G |
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| PassFan |
Keep in mind that 100db is at 1 meter. At 2 meters it drops to 94db, at 4 meters it drops to 88db.
Every doubling of power gives a 3db increase. Every doubling of distance takes 6 db.
So, it depends on the room as well. Still though, unless your in a huge family room it should be loud enough. Your bass response will depend on the amp design and not the amount of power you push. Some say a SE 300B, or 2A3 is lacking in that area. I could'nt say as I've never heard one of them. Good Luck;) |
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| G |
Well my "listening room" is about 12'x15' so maybe it will work out OK. Also it is a push pull 2A3 amp so hopefully the bass won't suffer.
G |
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| Joel |
| I have a 10'x12" living room, and a .8 watt power amp. It's plenty loud, and has lots of bass. I think you'll be fine. |
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| dice45 |
G,
if you don't want your eardrums to kiss each other, a PP 2A3 will be fine and if the amp is built properly, you will be happy with the low end reproduction. And with the rest too.
10Watts? only if the amp is running in AB1. On ClassA you won't get more than 7 Watts, rather 6 Watts. In classA you exactly get twice the SE power.
However, the better matched the tubes are, the better overall sound is.
So: don't go for expensive vintage 2A3 single plate, getting them match will make you broke. Hey, you could buy my 2 pairs of matched 2A3 single plate .. i got them for exactly that purpose ... then you have 2 pairs, enough for your amp. But after those are worn and you need new ones .. no, bad conscience, cannot recommend it.
You are better on with premium matched pairs of Sovtek 2A3 monoplate once you need nu tubes. And ... if the amp is designed to run with 15W plate dissipation max as is prescribed for pre1935 2A3, your Sovtek toobz run very conservatively. They rather make 25 than 18W plate dissipation. In fact, it's a 300B which just did miss the 300B marks. But it is sounding like 2A3. A very nice one. |
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| fdegrove |
Hi,
At home I use a PSE 2A3 amp with something no bigger than your Wharfedale at very satisfactory levels.
I never felt the need to push the volume control past 11.00.
I've been using the Svetlana 2A3s since the became available and in this amp they sound even better then any vintage 2A3 I threw in.
Definitely a lot better than the chinese stuff I used to use at first.
Ciao,;) |
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| ShiFtY |
I have used a 2W ECL82-SE amp with my speakers (89dB B&W DM100i bookshelf models) and it is quite loud, even with bass heavy music... Easily loud enough for reasonable listening levels, and actually gives a pretty good punch in the bass. Distortion only sets in at the absolute max (i use a little NFB) You can move the cones of the woofers by at least 2cm.
With 10W, you will be able to totally crank it. And if you are using sovtek 2a3s, you can run the plate dissipation up to 28W to get ~20W per channel in PP in class AB (pretty worthwhile if you use a little NFB).
~h~ |
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| G |
Thanks for the opinions guys. I think I'm going to get this for Christmas:
http://www.diycable.com/catalog/products/joplin.htm
It uses PCB's but it may not be too bad. I've read reviews on the Sovtek 2A3's and they sound like they will fill the bill. I'm going to retire my NAD integrated and go all tube.
G |
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| fdegrove |
Hi,
| quote: | | I'm going to retire my NAD integrated and go all tube |
Needless to say you're going to be hooked never to return to the NAD again.
Join the club,;) |
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| Joel |
That's not a bad price.
| quote: | | Frequency response 5-48kHz (-3dB@5W) |
That's a dumb spec though. If the amp is rated at 13W, then they should give the response at 13W. Or at least within the 20-20kHz range.
Makes me think the response is probably in the toilet above 5W. |
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| PassFan |
| I hope you guys noticed the prices for shipping. The kits come from Hong Kong and shipping ain't cheap.:eek: |
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| G |
That's a very good point. I hadn't seen that. I'm not going to swallow that shipping cost for them. That's a shrewd business plan. Instead of importing the parts and stocking them you let the customer pay the duty on the kit. They won't be getting my money. I guess that narrows it down to one of Gabe's Kits. I really wanted a 2A3 amp though. Big bummer. :mad: I knew it was too good of a price.
G |
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| Brett |
| quote: | Originally posted by G
That's a very good point. I hadn't seen that. I'm not going to swallow that shipping cost for them. That's a shrewd business plan. Instead of importing the parts and stocking them you let the customer pay the duty on the kit. They won't be getting my money. I guess that narrows it down to one of Gabe's Kits. I really wanted a 2A3 amp though. Big bummer. :mad: I knew it was too good of a price. |
The shipping surprised me too. I thought with a US agent, they'd have stock and despatch from the US.
But why give up on a 2A3? Why not just scratch build it? It's certainly more effort in collecting all the parts, but there's not much in them. There was a thread here recently about the Ralph Power 6B4G (2A3 with a 6.2V filament) which lots of people have built and liked well. |
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| planet10 |
| quote: | Originally posted by G
That's a very good point. I hadn't seen that. I'm not going to swallow that shipping cost for them. That's a shrewd business plan. Instead of importing the parts and stocking them you let the customer pay the duty on the kit. They won't be getting my money. I guess that narrows it down to one of Gabe's Kits. I really wanted a 2A3 amp though. Big bummer. :mad: I knew it was too good of a price. |
DIYcable is acting as a distributor for Brian Cherry on these amps http://www.diyhifisupply.com/diy_kits/the_joplin.html -- they are probably quite good knowing Brian (ex-Pat Canuck), but the way they are priced from diycable leaves a bit to be desired. He would get more respect if the shipping was just buried n the price. Even $775 USD for the kit is probably pretty reasoanable. (and i think given the way things are laid out, diycable is responsible for all duties & custom's costs.
Now as a circuit board kit it is probably a pretty easy thing to put together.
What would it take to build one up from scratch using Hammond, or other NA iron supplier? Certainly P-P wiring has the potential to wring more out of the circuit. You could use an interstage phase splitter or Allen Wright's differential front-end or a number of others - we know Dice45 is using something like this already and having gathered together the 2A3s to build a PP has given it a lot of thot...
dave |
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| Ryder |
G said above: "I'm not going to swallow that shipping cost for them. That's a shrewd business plan. Instead of importing the parts and stocking them you let the customer pay the duty on the kit. They won't be getting my money. I guess that narrows it down to one of Gabe's Kits. "
Don't take it as "shrewd" in the sense of trickery. Brian (diyhifisupply) and Kevin (diycable) are both upfront people who bring a pretty good value to DIY kits.
I have talked to Kevin on this point in person. He has a small business. He can't afford to drop ship tons of the stuff and carry an inventory. He just cannot do it. The cost of doing that would be as much as shipping. Peolpe are not used to paying to ship and insure trannies around the world and so it freaks them out. Did me too a little until I talked to them
Both are good guys who are into it becasue they love it. Neither is out to make a killing of trick anybody.
Brian has a new forum at the AA and they would be more than happy to talk about it. http://www.audioasylum.com/forums/DIYHiFi/bbs.html
I have no ties to the place at all.
I've never had the chance to hear Gabe's stuff. I'm certain it's good. Gabe has a very helpful site if you are starting out in tubes..Worth the read from start to end. I like Gabe for that alone. Never met him.
I have an outline of diy online electronics info (live links) that might be a littel help if you are starting out. if you (anyone) would like a copy email me.
Cheers,
Craig Ryder |
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| G |
Iwould like to build a amp from scratch except here's the catch, I never have built one point to point wired, from scratch. I'm basically going to sell a whole bunch of audio stuff that I have bought on Ebay and finance a kit so that I can actually listen to a tube amp. I have been learning and studying and buying parts to build something for about two years know and I am no closer to getting something built than I was two years ago. I guess that I have gotten to the point that I am so exasperated at not having anything to show for my money and time(my fault) that I'm ready to build a kit so I have something to listen to while I continue to learn. I'm not going to give up or anything. It's just that I'm ready for some results and some Diana Krall being played through a reasonably good tube amp(although she sounds fine through a NAD integrated also). At this point I'm not sure of my ability to pit together a tube amp well enough that it will sound good with no hum and all of that good stuff. I do have some output transformers from an old Fisher X-101C that I can use for a 6B4B Push pull though. Like I said I'm not giving up, just taking as step back and regaining a little focus. Indecision is a pain.
G |
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| planet10 |
| quote: | Originally posted by G
NAD integrated |
I forgot to ask which one.
dave |
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| G |
NAD 3300 Monitor series integrated with a NAD 5300 Monitor series CD Player. Are you in the market for one?
G |
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| planet10 |
| quote: | Originally posted by G
NAD 3300 Monitor series integrated with a NAD 5300 Monitor series CD Player. Are you in the market for one?
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No, but my backup amps are those out of a pair of NAD 7020s.
dave |
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| PassFan |
| There is a 2A3 plan at the Angela Instruments site that looks pretty simple. You mentioned Gabevees kits, I have built one of them and they are simple and quick to finish as Gabe installs and wires almost everything for you. His MAG1515 is an unbelievable sounding amp. It's not a 2A3 but if you want to experience a tube amp blowing away any solid state you've ever heard then this is the one.:cool: :D :D :D |
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| Robert Morin |
| quote: | Originally posted by G
Iwould like to build a amp from scratch except here's the catch, I never have built one point to point wired, from scratch. I'm basically going to sell a whole bunch of audio stuff that I have bought on Ebay and finance a kit so that I can actually listen to a tube amp. I have been learning and studying and buying parts to build something for about two years know and I am no closer to getting something built than I was two years ago. I guess that I have gotten to the point that I am so exasperated at not having anything to show for my money and time(my fault) that I'm ready to build a kit so I have something to listen to while I continue to learn. I'm not going to give up or anything. It's just that I'm ready for some results and some Diana Krall being played through a reasonably good tube amp(although she sounds fine through a NAD integrated also). At this point I'm not sure of my ability to pit together a tube amp well enough that it will sound good with no hum and all of that good stuff. I do have some output transformers from an old Fisher X-101C that I can use for a 6B4B Push pull though. Like I said I'm not giving up, just taking as step back and regaining a little focus. Indecision is a pain.
G |
I am crying as I read this.
What! you are selling gear to dabble in DIY?
Why don't you build a amp on a board of wood first. Try a simple PP design with some 6s4 or 6bl7. see if you like it. Then take the same tubes and reconfigure them to SE or better yet parafeed.
since you have op transformers the only other thing that is a few bucks is the power supply transformer.
this project should cost only about another 200$ tops.
Robert Morin |
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| G |
I used to have a Bogen receiver that used PP 6BQ5's and 12AX7's and it sounded far better than the NAD equiptment that I have now. In my opinion anyway. I'm not selling everything. Just enough to get the kit. I don't think that I will be sacrificing all that much. It's not like I'm never going to build anything. I just want to build a sure thing and get that under my belt and go from there. No I'm not throwing in the towel. I will have a PP 2A3 or 6B4G amp. I want to hear what all of the commotion is about with DHT's. Besides I really don't have room for everything that I have now. I can only listen to one thing at a time.
G |
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| Robert Morin |
| quote: | Originally posted by G
I want to hear what all of the commotion is about with DHT's
G |
IMO the commotion about DHT's is a fad. MANY of the older (pre wwII) tubes sound really good because the assembly was less rushed then.
Robert Morin |
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| Gunderz |
Hmmm... I just have a simple question....
Does really doubling in power give an 3dB increase?
I thougt that doubling the power would give an 6dB increase.
For power is the product of current and voltage, and doubling the voltage would give an 3dB increase, and the same with voltage.
And if we follow the rules for logarithms we will get 3dB+3dB=6dB, an 6dB increase.
What am I doing wrong in this assumption?? |
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| Robert Morin |
| quote: | Originally posted by Gunderz
Hmmm... I just have a simple question....
Does really doubling in power give an 3dB increase?
I thougt that doubling the power would give an 6dB increase.
For power is the product of current and voltage, and doubling the voltage would give an 3dB increase, and the same with voltage.
And if we follow the rules for logarithms we will get 3dB+3dB=6dB, an 6dB increase.
What am I doing wrong in this assumption?? |
a gain of 2 in power is 3db, a gain of 2 in voltage is 6db
Robert Morin |
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| Gunderz |
oki...
I understand... thanks |
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| planet10 |
| quote: | Originally posted by Gunderz
Does really doubling in power give an 3dB increase? |
Yes.
dave |
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| Thatch_Ear |
If you want to build something at a fair price then I think Gabe has a goog line of kits and truly the most time consuming part about building something is not doing a layout or any of that stuff it is getting all the parts together.
As far as building a kit I would recommend that you just forget PP and go SE and leave out all the stuff in the middle. You can get plenty of power out of a 6L6 and they are easy to come by. 6CA7s are great tubes in SE.
If you want to build PP drop me an email. I have an unbuilt and a needs rebuilding pair of Heath Kit A9-Cs mono blocks I want to get rid of.
Seriously though I would rather have a SE 6L6 than a PP 2A3. What you loose in power you more than make up for in pure listening pleasure. Heck of a lot easier to build too.
I am not familier with KEFs but I did go out and listen to their new line a month or so back. You have the TOTL tower? Reason I ask is that is is not hard to bi-amp speakers and running the mids/highs with SE and running the woofers with your NAD ought to sound very exellent in deed. |
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| ashok |
Is there any chart on the web that lists out the maximum power available in SE and PP mode from the following tubes.
2A3
6L6
300B
EL84
EL34
Thanks.
Ashok. |
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