mobile homeless Posted February 20, 2002 Share Posted February 20, 2002 Ok, this JOLIDA 102B is a nifty little amp that will get you some nice sound for not that many ducats. I happen to love the EL-84/6BQ5 output tube and this really simple integrated comes equiped with this very valve in push pull configuration. No, it does not have tube recitification but it is a nice, reasonably well-made amp that should give you about 15 tube watts, plenty for the vintage or high senstivity horn users here. Tube rolling will bring a great improvement here, depending on what is with it (on further examination - ie LOOKING, I notice it comes with Telefunken 12AX7 and Sovtek EL-84 - Telefunken are very sought after although I like Mullard 12AX7 better..but better than Chinese by long shot - Sovtek EL-84 can be improved upon easily for not too many $$); also, there are several mods that can be performed if you so desire to make this little swine bring on some improved sonics ie bypass balance, better volume pot, HEXFRED rectifiction...etc. IT is an integrated amp with a passive volume pot located within the chassis. Offer $325 and see what happens. http://cgi.audiogon.com/cgi-bin/cl.pl?ampstube&1019064063&class&3&4& kh Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point CD Player Rega Planet Preamp Cary Audio SLP-70 w/Phono Modified Amplifier Welborne Labs 2A3 Moondog Monoblocks Cable DIYCable Superlative / Twisted Cross Connect Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover system one online / alternate components / Asylum Listing f>s> This message has been edited by mobile homeless on 02-20-2002 at 12:25 PM Quote Link to comment Share on other sites More sharing options...
Colin Posted February 20, 2002 Share Posted February 20, 2002 Thanks for the alert! ------------------ Colin's Music System Cornwall 1s & Klipsch subs; lights out & tubes glowing! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 20, 2002 Author Share Posted February 20, 2002 The little Jolida was not a casual suggestion. I really think this would make a SS die hard wanting to get into tubes for the first time very happy. The EL-84 is a great tube and the amp is very simple. I think it would make a very good partner to the Heresy as any of the other vintage Klipsch. I seriously think this would be good buy and worth some of you waiting around for EICOs to perhaps look into for a sampling. I think you might be surprised. The fact that it has a volume pot built in is all the better. kh Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2002 Share Posted February 21, 2002 I'm not exactly clear on what the importance is regarding the type of rectification. Doesn't a rectifier just change AC to DC? ------------------ deanG Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2002 Author Share Posted February 21, 2002 That's funny...I always assumed that good sound depended on just one component... Lordy. Given countless casual and not so casual hours of listening to all sorts of tube circuits from vintage to modern, single-ended to push pull, low fi to hi fi, I would like to add (quite casually if I may be so bold) that I have found that tube rectification sounds more natural and true to the music than solid state, even when done with the latest choke input, quality capacitors, with HEXFRED high speed/soft recovery devices combined with a snubber; and this as about as good as solid state rectification can get. Many of my DIY cohorts prefer solid state done up in this fashion as they claim it has more control over the bottom end while retaining the good quality of tube rectification. I simply do not agree although I will admit it does sound much better than the lessor implementations of SS rectification. I have had many solid state rectified units pass within my system. And with my admitted Liberal Arts background with painfully little formal electronics training besides the self-taught variety (being an engineer in a radio station for 8 years helped), I have managed to muddle through upgrades of several SS rectified units. It actually is not that difficult to convert the rather harsh sounding SS devices to the less harsh, high speed/soft-recovery HEXFRED approach. Indeed, these parts are relatively inexpensive. In all the solid state rectified amps I have done this conversion on, the sound has improved in that it is closer to the more relaxed natural quality of tube rectification. Still, I personally still hear a difference, the kind of difference that presents itself in this overall manner of presentation. To me, good tube rectification (which is getting harder to find), has this natural, relaxed, bloom to the sound. Simply put, it has less of that solid state signature, which though there in subtle way, does contribute to the overall signature of the amp whether integrated or separate, single-ended or push-pull. The sound with SS takes on a subtle stressed sound to it... that is evident under longer listening sessions, even if not used to it or looking for this aspect. It is getting even harder to find tube rectification in tube preamps these days (compared to tube amps)Granted, the expense is much more, and the efficiency is far less, but the sound is worth it. Another great benefit of tube rectification in amplifiers is the slow start warm up of the rectifier tubes (some more than 30 seconds to come to full power as the cathode heats up letting the voltage increase) which REALLY increases tube life as the blast of voltage is not dumped all at once, which puts tremendous wear on valves. There are ways around this and ye olde standby switch can help here. But the ultimate soft start nature of tube rectification is an added bonus. So to me, even given the added expense, if you want the ultimate from a given "circuit" with all things being equal, there is nothing that beats (as of yet to my ears) tube rectification. kh This message has been edited by mobile homeless on 02-21-2002 at 02:09 PM Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted February 21, 2002 Share Posted February 21, 2002 Mobile, good post (as always). Quick question ... My AE-25 comes with an on/off switch and a standby switch. Would I improve the life of the tubes by just switching it to standby when not using? I listen to music everyday that I'm home so the max it would sit idle is 18 hours or so. When I'm on the road, I'd just shut it down. Just curious. Chris Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2002 Share Posted February 21, 2002 Would you happen to know what my beloved Superamp employs - can't seem to find much detail on the circuit design. ------------------ deanG Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2002 Author Share Posted February 21, 2002 A definite YES here with the STANDBY. That is one of the GOOD things about Cary products (and some AES products); almost all do use the standby switch with both tube and solid state rectified units. The Standby switch does indeed control the B+ voltage and when it is engaged (standby on), only the filiment voltage is on the tubes leaving the unit warmed up. Use this standby switch and you will put less wear on the tubes thus saving a bit of life compared to fully on... Also, and this is important, turn the power on first with the standby engaged...I would let it warm for a few minutes before disengaging standby. Another advantage to standby is that it can cut down on the turn on cycles and amp goes through. This is where a lot of wear and tear happens to tubes and circuitry...when turn on BURST of voltage enters. The standby can be used if not using the amp for awhile... to avoid that extra cycle. Then again, some say that if a tube or something goes with the amp in standby, there is more chance of damage than if off (Well, obviously). But Many amps do have a fuse protecting the transformer's primary so the fuse goes before that big ole transformer goes! One thing you will notice though, is that when you hit the standby if playing music, the amp will CONTINUE to play becaue the caps still have charge. Gradually, you will notice the sound fading and finally petering out in a bit of fuzz... This is normal. kh This message has been edited by mobile homeless on 02-21-2002 at 02:46 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 21, 2002 Share Posted February 21, 2002 HEXFREDS are Great for CD player rectification upgrades. And at a buck to two bucks a pop, cheap as well. So Mobile, do you think that adding SS rectification on a Tube amp/pre amp contributes to that grainy SS sound that is considered 3rd Harmonics? And the Harmonics that relate with the third? I'm sure that is what you probably notice. THANX! This message has been edited by mike stehr on 02-21-2002 at 02:37 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2002 Author Share Posted February 21, 2002 Hey Deang, your old AES "Superamp" uses solid state rectification. Like I said, if done well, solid state rectification can be fine; I just personally prefer tube for the added natural quality. There are a few owners of the AES Superamp in this forum. Remember, this amp simply started out as a stock AE-25 push pull EL-34 amp. Here is ole Dennis with some biased comments on why he thinks the "Superamp" is so special-Yep, it's rather long with some technical thrown in for those so inclined. Be warned, it also reads as a SUPERAD for the SUPERAMP: "For the technically minded, a review of the circuit is in order. Your new Super Amp operates in a class A mode. The output stage KT-88 tubes are self biased (auto bias) with a separate 390 ohm non inductive 5 watt resistor and 330 MFD capacitor combination on each tube. This bias network also has a 2 MFD film and foil capacitor bypass. Utilizing this bias network will permit the user to try many different types of output tubes if desired. Some of the choices may range from EL-34s, 6550s to 6L6s. One might even wish to listen with 6V6s. All these output tubes will present their own sonic signature. There is no bias adjustment required when listening with these different types of audio tubes in the Super Amp. The output power is 25 watts in the ultra-linear mode with KT-88 tubes. With a simple wire change at the tube sockets of the output tubes, you may wish to strap the KT-88s in the triode mode. This will give you 15 watts of triode power each channel. In the triode mode you will have the sweetest sound from the Super Amp. The output transformers on the Super Amp are the most important component in the amplifier and have been specifically designed by Cary Audio for use in the AE-25 Super Amp. We have taken an approach in the output transformer design, not dissimilar to the single-ended amplifiers we design and produce. The primary and secondary windings on portions of the output transformer are wound in a bi-filer process with the two inductors interleaving sixteen times. The bi-filer wind (two conductors wound at the same time) will yield the closest balance and coupling of any design currently utilized in vacuum tube output transformers. The E/I laminents used are silicone impregnated hipersil steel contributing to the extremely low loss of the Super Amp output transformer. The above process is similar to the single-ended air-gap design found on the Cary single-ended output transformers. A balanced drive signal is applied to the control grids of the KT-88 output tubes from the 6922 (6DJ8) driver tubes. These driver tubes sit on top of a pair of 6CG7 dual triodes as a current source. The 6922 tube is configured in a dual differential network that operates in the following manner: The first section of the dual 6922 tube is direct coupled to the input signal from the system preamplifier. The drive signal is amplified through this first section in a class A grid driven circuit with the output signal inverted 180 degrees out of phase at the anode and then coupled to one half of the push-pull bank of KT-88s. At the same time the second half of the dual triode 6922 is cathode driven in a grounded grid non-inverting class A gain stage coupled to the other half of the push-pull bank of KT-88s. With this network the balance is a perfect plus and minus dual drive signal to drive the final output KT-88s in a balanced push-pull configuration. With the simple deletion of one resistor and capacitor at the 6922 tubes socket, the Super Amp becomes a true balanced amplifier that may be driven by a balanced input signal. The Super Amp is offered as an option in the balanced configuration with XLR input connectors. ($125 option) The power supply transformer is designed to operate at a 200% continuous commercial service at the full rated 50 watt output level. The high voltage power supply section is a full wave center tap configuration (not some cheap voltage doubler as used in many competitors amps) to a two stage PI network with two filter chokes, one for each channel. This dual high voltage supply feeds the final output KT-88s. The AE-25 Super Amp is a zero global feed back design. The only thing hooked to the secondary winding of the output transformer is your audio system loudspeaker. You will immediately notice on female voices the lack of syllable sibilance. Music will tend to float between and behind the loudspeakers. You may be hard pressed, from your listening position, to hear any of the music coming from the loudspeaker itself. Bass notes will be full and exhibit sound stage decay. You will be able to play the Super Amp beyond its power rating without discernible clipping. These are just some of the musical benefits of listening to a properly designed tube amplifier without feedback. A great deal of attention during design of your new AE-25 Super Amp was concentrated on the "overload recovery" ability of the amplifier. The ability of an amplifier to instantly recover from clipping is much more important than is commonly believed. In the power war of amplifier manufactures the mentality is focused on high and then even higher power output to solve the clipping problem. When in reality the most critical aspect is how fast of a recovery an amplifier can achieve after overload. With the incredible dynamics range of live and in turn recorded music, even 2,000 watts of power is not enough. Most of the music being listened to in an average home listening room is only requiring about 3 watts of power. It is on the transients of loud low frequency program material that tremendous signal voltages will appear at the input of the amplifier. It is in this situation that the overload recovery ability of an amplifier is of critical concern. The Super Amp extols its merits in the ability to handle transients and instantaneously recover from brief or even extended overloads. The Super Amp will overload symmetrically at any frequency in the audio bandpass. The Super Amp will also yield faithful reproduction of extremely low frequencies at full output levels. Power transformer, power supply regulation and output transformer design and careful shaping of the overall frequency response curve all play a very important part in the ability of the Super Amp to recover quickly when over loaded. If one were to monitor the high voltage rail voltage (310 VDC) of the Super Amp during soft and also loud music passages it would be found there is no more than a volt or so change from soft to loud passages. Another technical feature of your new Super Amp is stability. The Super Amp may be operated with no load (without speaker) without damage to the amplifier, output transformer or tubes. f>s> Ole Dennis... He got a bang outta that, I'm sure. You have to dig a bit to find this text, though. kh This message has been edited by mobile homeless on 02-21-2002 at 03:07 PM Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2002 Share Posted February 21, 2002 Impressive - wonder what in the hell he's talking about ------------------ deanG Quote Link to comment Share on other sites More sharing options...
Mike Lindsey Posted February 21, 2002 Share Posted February 21, 2002 I think he got you confused with Chris. It must be tough for him to keep up with all the tube gear everybody has been buying lately. I know it would me... Mike Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2002 Share Posted February 21, 2002 No - Mobile had it right. I have a Superamp on the way and I asked him if it used tube rectification. My comment wondering what the hell he was talking about was aimed at Dennis Had (or however you spell it). ------------------ deanG Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2002 Author Share Posted February 21, 2002 deang and Chris BOTH have Super Amps... Having met Dennis (my Cary preamp and old ProAcs were his personal items), I can say he does do a good job of explaining tube audio to the beginner. I have seen him several times field questions and not resort to engineer speak, meanwhile still conveying the technology of the design as well as why it might sound better or worse. If you are ever confused about single-ended, he is a great one to present it in layman's terms. While I dont think his SET amplifiers are the best single-ended has to offer (though still very good), Dennis Had is the one almost soley responsible for putting the SET amplifier on the commercial map, thus giving it exposure to a wide audience. The Japanese have been into it for YEARS before. In talking to Dennis, he has said several times that without the Far East during the early to mid 90s, Cary would have folded. He sent most of his product overseas which kept his company afloat as tube audio, especially single-ended amplification, was not as widely loved in the late 80s early 90s. Even up to 1994, SET was still very underground. Tubes have ALWAYS been popular with the underground and DIY contingent. Even at the most underground times, loons where out there messing with tube gear. Companies like Audio Research and Conrad Johnson also staid the course since the 70s when tubes were under the radar so to speak. kh This message has been edited by mobile homeless on 02-21-2002 at 03:44 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 21, 2002 Share Posted February 21, 2002 I didn't think that write-up that you posted from Dennis was TOO Technical. At least he didn't throw in the Math involved. That god for the Far East, I guess. Where would we be if it wasn't for the Japenese Love of old school Tube circuits. Quote Link to comment Share on other sites More sharing options...
Mike Lindsey Posted February 21, 2002 Share Posted February 21, 2002 Oops...my bad! Dean, could you please remind me what preamp you are going to be using with your Superamp? I know Chris has the AE-3 and I am very curious to hear his opinion on this combo with his Khorns. I would likewise be interested in your opinion of your combination with the RF-7's... Thanks, Mike ------------------ My Music Systems Quote Link to comment Share on other sites More sharing options...
Deang Posted February 21, 2002 Share Posted February 21, 2002 My Superamp is coming with a built in volume control. I have no idea what to expect. If I do buy a preamp it will be the AE-3. ------------------ deanG Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 21, 2002 Author Share Posted February 21, 2002 One interesting note. One of the owners of the AES AE-3 preamp is our own Ed (edster00). Ed decided to spring the extra ducats for the AE-3 Super Preamp DJH which, among other things, opts for TUBE rectification via an 6CA4 tube over the normal SS via the stock AE-3. But where does all this LEAVE the poor Jolida EL-84 Push pull amp that started this thread? Nothing exotic here and surely no tube rectification or HEXFREDS either (a lot of Jolida owners mod the HEXFRED later by the way). Still, I think this is a neat little amp with some decent transformers. I'm surprised someone hasnt given it a go. Of course, there are better amps out there and perhaps some better choices for 300. But this would make some solid state land locked loon happy! kh This message has been edited by mobile homeless on 02-21-2002 at 05:06 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 21, 2002 Share Posted February 21, 2002 Buy it for me Kelly! Just joshin'! Quote Link to comment Share on other sites More sharing options...
edster00 Posted February 21, 2002 Share Posted February 21, 2002 I can say that I am VERY happy with the sound of the AES AE-3 (DHJ version) preamp. I am sure you guys who are getting an AE-3 will be too. My AE-3 is feeding the Moondogs, but I was eyeballing that Superamp before I found the Moondogs at a good price. I am looking forward to your review(s) of the gear when you get it. ------------------ 2 Channel System: '78 Khorns w/ALK networks Welborne Labs Moondog 2A3 amps AES AE-3 Superpreamp DJH mods McIntosh MCD 7007 CD McIntosh MR-78 Tuner DIYCable Twisted Cross Connects DIYCable Superlatives (preamp/amp) DH Labs Silver Pulse interconnects (sources/preamp) f> s> Quote Link to comment Share on other sites More sharing options...
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