Posted by John Chleapas [ 68.162.212.207 ] on February 15, 2005 at 00:22:18:
In Reply to: Still a bit of a generalization, but... posted by Wayne Parham on February 14, 2005 at 15:01:37:
>I tend to agree. I've heard some really nice SET amps, but one thing I've started to realize is that they aren't cheap. The entry level SET kits I've heard had very little power and flabby bass or no bass at all. But if budget allows bigger tubes and iron, then I think SET becomes an attractive option.>
Wow. My two SET amps both make thumping bass. I have a 300b Welborne DRD and a 45 DRD Welborne. Both are mono blocks. The 300b is SS rectified and the 45 is tube rectified. I use JBL 4648A-8 twin 15" bass bins that are 100dB efficient. Just a casual observation that many who listen to SET for the first time may not have speakers efficient enough. This does not apply to you Wayne as your Pi speakers are eficient enough for SET. These Welborne amps will play on for a good 10 seconds after I switch them off so maybe their power supplies are also stouter? I have a small stereo 11 wpc 6V6 amp and that has much less bass to my ears than the 300b and 45 SET amps. This amp is used at my apartment on less efficient 93dB@1W JBL L300 speakers. These speakers can exhibit mucho bass with my highly modified 19wpc strapped in triode Dynaco ST-70.
>I think you can make a much nicer sounding push-pull amp for a few hundred dollars than a SET amp, so I think entry level systems might be better off running push-pull. The trouble for DIY is that SET is simple to build but requires more expensive components for good sound quality. A good quality push-pull amp can be made with cheaper components, but it's more difficult to build, and maybe that discourages DIY builders.>
I think you get what you pay for. Cheap iron is not a great start for any DIY project. See the Derek Walton site for plans for the inexpensive version of the JE Labs 300b. The inexpensive angela universal power transformer is actually pretty good. Again with better iron I think anyone will be happier with the results no matter if they are building SET or PP. As for parts count it is a fact that SET usually has a lower parts count. I would love to build the Gordon Rankin designed Baby O' some day. But the silver wound output transformers are about $800 each. Still these amps really look very well designed, and they have low parts count. Low parts count means easier building for dummies like me with a soldering iron.
>I guess I've come to the conclusion that if you have the budget, give SET a go. There are some great SET amps in the $2K range. Less than that, I'm thinking go push-pull.>
There are also some great PP amps in the 1K range like the used Klimo Kent 35 wpc EL34 mono blocks. I paid the princely sum of $995 for my pair on Agon last Fall. Ron Welborne sells some nice SET kits starting at under $1500. He sells built units that use the very good quality ElectraPrint output transformers for a little more loot. Both the kits and the built amps use Electraprint iron. I own 45 SET, 300b SET, EL34 PP, KT88 PP mono block amplifiers. I own a few stereo amps in my HK Citation 11, and two Dynaco ST-70 amps. I listen to both SET and push pull. Both modalities do things that I like. As long as it has tubes and is not made brand new in China I will listen to it. No, some higher end Chinese new gear is rated nicely. I cringe at the folks buying the lowest end Chinese tube gear that just might not stand the test of time. All audio is very subjective at its best. None more so than tube amplifiers and horn speakers. I am a believer in buying vintage tube gear and enjoying it. For example I bought a 20 year old Conrad Johnson Premier 4 that uses 8 Mullard EL34 tubes and makes 100 wpc. Three years later I sold it on Agon to a doctor in MD who loves it for what I paid for it. Same with my HK amp and other higher quality names that tend to hold value. Some like my Fisher FM-1000 tube tuner, and other collectible tube ones can even go up in value. The smart reason for buying better quality used tube amps is you can usually recover your investment if you do not like them. LOL, that is only true if you do not spend to much when you buy it, if it is worth less than you paid for it. Make any sense? Hey, as long as it glows listen to it! Have fun as this is a very short journey we are on in life. I really like the 2-way horns I got for my Dad. The horns are 31" x 31" JBL 2360A. The drivers in them are TAD td-4001. The bass bins are JBL twin 15" woofer 4648A-8. The horns are powered with the 45 mono blocks. The bass bins are still having a/b testing with the 300b SET and the Klimo EL34 push pull. The crossover is a marchand xm-126. It is a lot of fun to listen to vinyl and CD's on his stereo. His speakers at 6' tall are very SET friendely speakers with the 100dB efficiency. I powered both speakers with only 1.8 wpc and it made great sounding music. John C.