Area 51 Posted August 28, 2022 Share Posted August 28, 2022 On 8/26/2022 at 7:49 AM, henry4841 said: It is being hard for me to sell this Sweetie after I have finished it. Like one of your kids leaving for college. Never done it before, selling an amp I have built. But the plan is to pack it up and send it on it's way first of next week. Page 17 of Little Sweetie Forum amplifier project thread. Quote Link to comment Share on other sites More sharing options...
Area 51 Posted August 28, 2022 Share Posted August 28, 2022 On 8/26/2022 at 7:49 AM, henry4841 said: the plan is to pack it up and send it on it's way first of next week. Page 17 of Little Sweetie Forum amplifier project Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 28, 2022 Share Posted August 28, 2022 5 minutes ago, Area 51 said: Page 17 of Little Sweetie Forum amplifier project But that is not the one Henry just built. Which one are you getting? Quote Link to comment Share on other sites More sharing options...
Area 51 Posted August 28, 2022 Share Posted August 28, 2022 That is not the one Henry just built that I am getting. I made the mistake of conflating the picture and text in that post. My bad. Quote Link to comment Share on other sites More sharing options...
jjptkd Posted August 28, 2022 Share Posted August 28, 2022 On 8/26/2022 at 1:12 PM, Area 51 said: Primary preamp is a Schiit Freya +. How do you like this preamp? Been thinking about trying one out they look good and get great reviews thanks. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 28, 2022 Share Posted August 28, 2022 1 minute ago, Area 51 said: That is not the one Henry just built that I am getting. I made the mistake of conflating the picture and text in that post. My bad. I understand. You are excited as you should be. I think you are going to like that amp. Quote Link to comment Share on other sites More sharing options...
Area 51 Posted August 28, 2022 Share Posted August 28, 2022 2 minutes ago, Curious_George said: I think you are going to like that amp. I think so, too. Quote Link to comment Share on other sites More sharing options...
Area 51 Posted August 28, 2022 Share Posted August 28, 2022 3 minutes ago, jjptkd said: How do you like this preamp? Been thinking about trying one out they look good and get great reviews thanks. I like it but, honestly, I don't have a lot to compare it to. (Yes, I'm full of Schitt). I also have a Schitt Saga+ and that's pretty much the extent of my experience. It's all still new to me. 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 28, 2022 Author Share Posted August 28, 2022 Guys I am glad you have enjoyed this thread. I think it has been a success. Every one has been respectful and polite with each other for the ones contributing to this build. My intention was just to build this one being it has been a thought of mine for a number of years. Maynard and I discussed this many years ago. I actually had the intention of putting some Aleph J boards in a proper chassis before taking this project on. I started putting together the parts needed to remove the Aleph J boards from the wood test chassis, shown on an earlier post, and giving it a proper home. In fact before starting on this build I had already received one those expensive chassis to start that build already having a transformer and power supply board. Building a class A First Watt clone is not cheap. Just the case alone with the holes already drilled for the boards is $344. https://diyaudiostore.com/collections/frontpage/products/deluxe-ultimate-amplifier-chassis?variant=39313326211145 I buy a cheaper one just like the one above but without the holes already drilled and tapped and drill and tap them myself. Like I have said many times on the thread I am just doing this as a hobby to enjoy myself. Being that there is an interest I am considering taking my time and building another Sweetie in the near future but different. A Sweetie with lipstick on it using premium parts. Much like some of my other tube builds. Like this. https://community.klipsch.com/uploads/monthly_2022_08/P1030824.thumb.JPG.ff722ad35dce7ddc98b8291091efa6ea.JPG I know an EL34 build would attract more people wanting one but to be perfectly honest without some NOS tubes I do not believe it would sound as good as a 6Y6 of old in vocals and midrange. To me that is the most important thing with any amplifier. The difference in price of a premium EL34 amp and a premium Sweetie would be a few dollars more but not a significant amount. In other words I had rather build a premium Sweetie. I do not know if there would be an interest here for such a thing. I do not want to turn out a lot of the same old thing. That is work and a job of which I want no part of. I am getting by with the meager income I have. In other words not for the money but for enjoyment. I like building tube amplifiers. I have a local dealer that sells LP's that also takes in repairs of old audio equipment and subs it out to people he knows that repairs them. He asked me about doing some repairs and I quickly told him in a polite way not interested, do not want a job. But he did say if I wanted to I could bring him an amplifier on consignment and he would sell it taking a commission. For anyone with a old receiver or amplifier a local LP dealer may be a good place in your town to ask if they have anyone doing repairs for them. If there is an interest in a premium Sweetie you can PM me but I am not taking orders. That would be a job. And I will not say I will build it for you. If I build a premium Sweetie when I finish it I will offer it for sale but am not under any obligation to build it for a specific person. In other words I just like building amplifiers and do not want to build the same thing over and over. In other words no pressure. Too old for that. Just some thoughts of an old builder of amplifiers for himself over the last ten years or so. 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 28, 2022 Author Share Posted August 28, 2022 Just thought I would add, the reason it has been 2 years or more since I have built a tube amplifier is that I have already built all the tube amplifiers I ever wanted for myself. Just to hear what they sound like. I think I counted 11 working ones in my house right now. I do not want to part with any of them. Might say I am a hoarder of amplifiers. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 28, 2022 Share Posted August 28, 2022 Henry asked for my opinion about sharing a cathode resistor between the two output channels. Well, I have never tried it! I imagine it would result in a little crosstalk between the channels which, depending on the result one is looking for, may not be bad in that it could provide a tighter center image than dual mono would provide. It may be similar to using a shared B+ rail to feed both output xfmrs ( there was a big discussion about this on DIY audio maybe 8-9 years ago which I will try to find). Another consideration is what would happen if one tube gets weak or craps out. Remember, the value of the shared cathode resistor is half of that for a single channel. So, if the current through it decreases significantly, the bias will be off. For the minimal difference in cost, I don’t see the point of not using separate resistors and caps. Regarding AC vs. DC input coupling, I have always favored the former after encountering devices with leaky output coupling caps spilling DC. Also, my preferred driver is a grid leak biased triode which, of course, requires AC coupling. The 6SJ7 can be biased that way as well although I have not yet tried it that way. If anyone wants to build but finds chassis prep to be more than they want to tackle, the Spudkit may be a nice alternative. Spud amps have the advantage of only using a single amplifying device per channel. I have done a lot of work with pentode and triode spuds and elimination of a driver tube can result in some amazing sound, especially if speaker impedance variations are controlled in the pentode units (a 27 ohm resistor across the speaker terminals is all that is needed). https://spudkit.com/ Enough rambling for today (my wife thanks Henry for convincing me to spend a few minutes on here- she thinks I don’t have enough to do 😬 Maynard 2 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 28, 2022 Author Share Posted August 28, 2022 There you go guys. I'll stick to added parts for my builds instead of saving a few bucks here and there. But I am not in the amplifier business like Deckert at Decware. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 28, 2022 Author Share Posted August 28, 2022 Guys I have been doing some thinking about a premium Sweetie. Those upright PS transformers are pricey for a stereo build. I really like the toroids from Antek but to make room underneath for the Hammond OPT's it is going to take a big chassis for that big Toroid and OPT's to be underneath. There are retail sellers of amplifiers who have their toroid on top showing but if I build a premium Sweetie it must be pleasing to the eye as well as sounding good. My thoughts are two mono's in one chassis using two of Maynard's choices for PS transformers. Two PS transformers and two PS sections bridge rectifiers, caps and resistors etc. This would be two complete and separate amplifiers in one case. I would put the PS transformers on top in plain view and the OPT's underneath. This build would be using what is called aluminum sheet plate instead of ready to use Bud chassis like my last build. The aluminum sheet plate will sit neat inside a hand cut dovetail cherry wood case. That sheet plate has gotten rather pricey since I last bought any. I do have one sheet already but will need to buy another. If I decide to do this build I do not know if there is any interest of seeing me build it in steps like this last Sweetie on this forum. I will let you guys decide. Quicker not posting in stages but I am way past being fast doing anything, 73 years old. I am just enjoying the activity breaking the monotony of the day. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 28, 2022 Author Share Posted August 28, 2022 Just checked that spud kit Maynard is talking about. Looks really good for a first time builder of a tube amplifier. Much simpler than sourcing all the parts like I, and other experienced builders, do. Have to sound good. Never heard a bad sounding tube amplifier. Good place to start your diy tube amplifier building. $450 for kit. https://spudkit.com/?page_id=13 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 29, 2022 Author Share Posted August 29, 2022 Maynard, I seem to have forgot exactly how the 2nd grid on the 6Y6 tube works. I see it is positive in relationship to the cathode being it is attached to the positively charged plate through a resistor reducing the voltage. For beginners on Maynard's schematic it is R9 which is 100ohms. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 29, 2022 Author Share Posted August 29, 2022 If everything goes as planned my Sweetie, I just built on this thread, will be going to it's new home today. Big moment for an old man having never sold an amplifier before. I hope the new owner enjoys the sound as much as I do. I did my best building it with what I have learned the last 10 years of building amplifiers for myself. It seems there is always talk of most any amplifier design of getting more power out of the circuits. I just do not see the need myself. That is with our Klipsch speakers, especially the heritage line with a mid horn. I will be happy building the best sounding 1 watt amplifier I know how to build. The Sweetie fits that bill better than anything I have built or heard. They bass is good for the more "refined gentlemen" not wanting to shake the walls in the house. If shaking the walls is what one likes the best job for that is called a sub. I built my sub for reproducing really low notes. I bought a supposedly good 15 inch $200 speaker from Parts Express and put it in a big sealed box, 6 cubic feet. The only way a speaker can produce really low notes is it must have room to move a lot in a sealed box. In a smaller box the acoustic spring action will stiffen the action of the speaker making the bass quicker with better transient response but not so low. Those ported bass systems are tuned to a certain low frequency. My 15" sub speaker can get flabby sounding if it is pushed too hard but what I am looking for is really low notes and I am not one to push it real hard even though I have a 500 watt plate amplifier pushing it. With the pushing I am doing with it the upper low notes it produces are plenty quick enough to match the LaScala bottom end from say 100hz and under. I am just wanting a sub to take over where the LaScala bottom end starts to drop off. Talking about a port system or horn system in the Klipsch heritage line the difference in price of a port bass vs a horn bass unit is $6,600 in the heritage line. The price listed on Amazon for a pair of cherry Cornwall's is $6598. vs $13,198. for a pair of the cheapest horn load speaker in the heritage line the LaScala in cherry. The biggest cost factor between the two is the bottom horn bass unit. The bass you hear in the LaScala is going to be the best you are likely find on the market today. That is within it's limits. The K-horn is one step up from the LaScala will even go lower in the bass at a higher price. I love my horn loaded bottom end in the LaScala. I would never turn it into a ported system that many do on this forum. I paid for horn loaded bass and that is what I want to hear. Why sacrifice what LaScala does best by changing it to a port, kinda still horn, bottom end? I want to do what it's best job is. Hey guys that have changed the LaScala to a port system, nothing wrong with doing it but just not me. I bet it still sounds excellent after doing the change. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 29, 2022 Share Posted August 29, 2022 2 hours ago, henry4841 said: Maynard, I seem to have forgot exactly how the 2nd grid on the 6Y6 tube works. I see it is positive in relationship to the cathode being it is attached to the positively charged plate through a resistor reducing the voltage. For beginners on Maynard's schematic it is R9 which is 100ohms. The purpose of the screen stopper is not to reduce the voltage relative to the plate. In tubes which permit the same voltage on the plate and screen, this is unnecessary. Rather, in combination with the internal capacitance of the tube, it forms a RC filter to reduce the possibility of unwanted (parasitic) oscillation which occurs with some pentodes when used as a triode. Tying the plate and screen together, by increasing the surface area of the elements , also allows a slightly higher plate dissipation if someone wants to extract every last bit of power from the tube. Maynard 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 29, 2022 Author Share Posted August 29, 2022 Thanks for the explanation Maynard. I have read about pentode operation years ago but have only built maybe one or two of them. I like SET's and they make plenty enough power for my LaScala's. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 29, 2022 Share Posted August 29, 2022 1 minute ago, tube fanatic said: The purpose of the screen stopper is not to reduce the voltage relative to the plate. In tubes which permit the same voltage on the plate and screen, this is unnecessary. Rather, in combination with the internal capacitance of the tube, it forms a RC filter to reduce the possibility of unwanted (parasitic) oscillation which occurs with some pentodes when used as a triode. Tying the plate and screen together, by increasing the surface area of the elements , also allows a slightly higher plate dissipation if someone wants to extract every last bit of power from the tube. Maynard In my EL34 amp that I modified, if you don't use at least a 100 Ohm resistor from screen to plate (triode mode), the EL34 will ring like a bell. 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 29, 2022 Author Share Posted August 29, 2022 Thanks for joining in the conversation with your experiences George. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.