Curious_George Posted August 24, 2022 Share Posted August 24, 2022 . 4 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 24, 2022 Share Posted August 24, 2022 You seen this one. I built this one and it sounds really good. George has a complete guide on his website. Also a board a beginner can purchase. It is going to be more expensive than the Sweetie. http://tubelab.com/designs/tubelab-sse/schematic/ Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 24, 2022 Author Share Posted August 24, 2022 I am familiar with George's driver board. Good stuff no doubt, but I don't like mixing SS & tube circuits unless I absolutely have too. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 24, 2022 Share Posted August 24, 2022 Purist. 🙂 I do not mind letting a SS device circuit doing some of the job around the tube. Not supposed to contribute to sound. Hope you do like I did and document your build with pictures. Seems to be popular subject with some interest here. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 24, 2022 Author Share Posted August 24, 2022 . 1 Quote Link to comment Share on other sites More sharing options...
CWelsh Posted August 24, 2022 Share Posted August 24, 2022 I will be happy to help with a BOM, if needed. I like this trend toward DIY projects. I know it isn't for everyone, but some of us will definitely dig it, and it may inspire a new generation. I hope to inspire my 25 y/o grandson. He already has an extensive vinyl collection that emphasizes the 60s and 70s. 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 25, 2022 Share Posted August 25, 2022 14 hours ago, Curious_George said: As you know, the EL34 has tons of history. If you want to play with the circuits of the EL34 family of tubes George Anderson has done a lot of the work for you. Look at the charts. I just build from someone else's schematic. http://tubelab.com/designs/tubelab-sse/applications/ I look forward to following along if you decide to document the building process. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 25, 2022 Author Share Posted August 25, 2022 On 8/25/2022 at 7:06 AM, henry4841 said: I look forward to following along if you decide to document the building process. . 2 Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 25, 2022 Author Share Posted August 25, 2022 13 hours ago, CWelsh said: I will be happy to help with a BOM, if needed. I like this trend toward DIY projects. I know it isn't for everyone, but some of us will definitely dig it, and it may inspire a new generation. I hope to inspire my 25 y/o grandson. He already has an extensive vinyl collection that emphasizes the 60s and 70s. A BOM would be a big help. If you need anything further to start the BOM, let me know. I've tried to annotate as much info on the schematic as possible. By default, I usually spec standard metal film resistors since they are the same price as carbon film nowadays. I also use Rubycon or Nichicon electrolytic caps just because of their reputation and Orange Drops for the 0.22uF/400V coupling cap. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 25, 2022 Share Posted August 25, 2022 Nice, have you decided on what you are going to build with those new OPT's? I have some extra Hammond 125dse's I am thinking of doing a SET KT-88 build with. Just thinking, no solid plans what I am going to do with them. Searching through my box of transformers I think I have found an Antek PS transformer I might could possible use. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 25, 2022 Author Share Posted August 25, 2022 On 8/25/2022 at 8:32 AM, henry4841 said: Nice, have you decided on what you are going to build with those new OPT's. . Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 25, 2022 Share Posted August 25, 2022 Just now, Curious_George said: Since the transformers I got from Musical Power Supplies (MPS) are only rated at 50mA, I'll have to save them for a 6V6 type tube or a Little Sweetie when I get around to building one. Sweetie!!!!! You will not be disappointed with its sound for a 1 watt amplifier build. You can always tear it down and use the high price iron and big caps on another build only costing a hundred or two to play. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 25, 2022 Author Share Posted August 25, 2022 On 8/24/2022 at 5:03 PM, Curious_George said: The 12AV7 is also a common tube with a high/medium mu and NOS tubes are cheap and abundant. . 1 Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 26, 2022 Share Posted August 26, 2022 Nick, can you post your load line drawn on the triode plate curves? I can’t imagine getting more than a couple of watts from a 6L6 at the operating point you specified, and would venture that the distortion would be upwards of 8%. Thanks… Maynard 1 Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted August 26, 2022 Share Posted August 26, 2022 That schematic shows pentode operation, the screen is tied to B+ not to the plate. Hence the 8 watts output power. Triode mode one can expect maybe 4 watts. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 26, 2022 Share Posted August 26, 2022 10 minutes ago, captainbeefheart said: That schematic shows pentode operation, the screen is tied to B+ not to the plate. Hence the 8 watts output power. Triode mode one can expect maybe 4 watts. I was referring to the schematic Nick posted at the start of the thread. I’m not getting that old😃 Maynard Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted August 26, 2022 Share Posted August 26, 2022 4 minutes ago, tube fanatic said: I was referring to the schematic Nick posted at the start of the thread. I’m not getting that old😃 Maynard Yes I know you were asking for info on the triode strapped version. Just wanted to clarify about the 8 watt original pentode amp. With a perfect driver (no distortion) the EL34 triode strapped with this operating point will be about 3 watts at 5% THD Clipping occurs at 4 watts. Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted August 26, 2022 Share Posted August 26, 2022 Just did a simulation of the entire circuit and the driver doesn't change anything drastically. With 1.2v peak input you'll get 3.125 watts output @ 5% THD Quote Link to comment Share on other sites More sharing options...
captainbeefheart Posted August 26, 2022 Share Posted August 26, 2022 1 hour ago, tube fanatic said: I can’t imagine getting more than a couple of watts from a 6L6 at the operating point you specified, and would venture that the distortion would be upwards of 8%. You were dead on with the triode wired 6L6. I ran the circuit with a 6L6 this time and the results were: At the same input of 1.2v peak, power out is a hair over 2 watts at over 7% THD. The EL34 triode strapped does sound pretty good and is the clear winner, well at least for me I'd use the EL34 with this circuit. Quote Link to comment Share on other sites More sharing options...
Curious_George Posted August 26, 2022 Author Share Posted August 26, 2022 . 1 Quote Link to comment Share on other sites More sharing options...
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