I know this amp isn't even out yet, but for those that understand this stuff a lot better than I do, how hard would it be to mod this amp to accept 6922 (and associated tubes) in the driver slot?
I've got quite the collection of these tubes, including the Russian variants (6H23-EV, 6N1P-EV) as well as several 6922's, 6DJ8's, and some 6FQ7's. I know these are not all exactly the same, but many designs allow them to be used interchangeably. Would it be a nightmare to get the Simple P-P to play nice with these tubes?
Also, I've got several of the Russian variants for the EL84 (SV-83/6P15P-EV as well as the 6P14P-EV) and I'm hoping those will also run without issue.
This amp would be a lot cheaper if I could use what I already have.
I've got quite the collection of these tubes, including the Russian variants (6H23-EV, 6N1P-EV) as well as several 6922's, 6DJ8's, and some 6FQ7's. I know these are not all exactly the same, but many designs allow them to be used interchangeably. Would it be a nightmare to get the Simple P-P to play nice with these tubes?
Also, I've got several of the Russian variants for the EL84 (SV-83/6P15P-EV as well as the 6P14P-EV) and I'm hoping those will also run without issue.
This amp would be a lot cheaper if I could use what I already have.
The 6922 and its siblings have a different heater wiring than the 12AT7. This would require hacking the PC board. The gain is lower and the resistor values would have to be changed. Therefore I wouldn't recommend trying this.
I have used some 6P14P tubes I got from a Ukrainian seller on Ebay. They work as well as most of the tubes being sold as EL84's. This means that you can use them at the EL84 ratings without a problem and get about 15 WPC. I have been told that the "EV" version is tougher but I have not tried them. I have cranked the current production JJ's and several vintage 6BQ5's far in excess of the ratings to get as much as 30 WPC without glow.
I have 100 PC boards and several sets of parts kits sitting here and I am already paying the credit card interest for the privledge. I am as anxious as you are to start selling them. The problem lies with the assembly manual. As I was nearing completion of the manual, Microsoft (and my web hosting company) discontinued support for the Front Page Extensions that my web site uses. This broke the web site and prevented me from posting any new information. Much discussion led me to believe that I had to completely rebuild my web site using a new program. I started down this path, but had to make an unscheduled trip to West Virginia two weeks ago. My laptop went with me to work on the web site. I just returned yesterday.
During this time I found a way to cheat and force Front Page to succesfully update the web site. It is a very slow process, but avoids rebuilding the entire web site. The broken links and missing link bars should already be fixed and I will be adding new pages as fast as I can copy them out of my newly built but unfinished web site. Each update requires completly reloading the entire web site to the hosting company just to change one page. This takes about two hours over a DSL connection!
I'll have to find another project for those.
Thank you for your time and perseverance in working through your Web site's issues. The Simple P-P is the amp I am waiting to build next. In the meantime, I am modifying my cheap Suppo Golden Voice EL84 amp from China. It sounds really good, but I believe the Simple P-P will be superior to the Suppo amp.
Perhaps, you might consider a pre-order program to hep you shoulder the financial responsibility of all those PCBs and kits you are assembling. I would be willing to send a PayPal payment as I know you're an honest guy.
Just a suggestion, but you can use an FTP program like Filezilla to upload one or two files at a time. May not be practical for major updates, but changes to a file or two it will save you a lot of time. FileZilla also has some smarter upload techniques using modification times as a guide. It has been a useful tool for website updates in the past.
Another suggestion: "Contribute". Have found this easy and effective. Looks like they have a try it version.
web publishing software, creative web development | Adobe Contribute CS4
web publishing software, creative web development | Adobe Contribute CS4
Russ, I appreciate the time and effort that you have put forth trying to help a web site dummy with this. I went down the easy path 7 years ago by letting Front Page manage the navigation structure of the web site. It was too easy. There is a site map structure in FP and I just drag the page icon to where I want it and FP does the rest. The bad part is that this requires the use of the FP uploading software. I am sure that there is some FTP script going on in the background, but I just push the "publish site" button. This only works when the FP extensions are enabled at the host site. It also does not allow for manual FTP sessions. The default setting does a compare of the local (my computer) site to the remote (Hostway's) site, and only uploads the pages that have changed. This has worked fine for me until September. Single page changes take about 2 minutes.
In September the local hosting company that I used (Value Web) was purchased by Hostway (Chicago area). They moved my site, and stuff happened, or more correctly didn't happen. I got a tech support guy to re-enable the FP extensions on my site, but he said there would be no guarantee or support. Multiple attempts to post new material resulted in a broken web site.
While I was in West Virginia one night with nothing much to do (6 inches of snow and sub zero wind chill) I decided to bug one of Hostways tech support guys. I guess he didn't have much to do either, so we figured out how to tell FP to force the organization structure of the local site on the remote site. The basic procedure is to completely delete the remote web site, forcing FP to upload a new copy of the entire site. Slow, but it works.....for now. Web site users may experience "404" errors during the time that I do this (usually late night EST).
That program was suggested by one of the Dreamweaver experts at work. I don't have it, and it looks like it would cost me about $160 to get it because I don't qualify for an upgrade.
I hated to give M$ any more money after buying Vista, but $69 for an Expression Web 3 upgrade wasn't too bad. I have built some decent pages with it for the new site, but I still haven't figured out just how I want to organize it all yet. Rather than start with one page and stick 7 years worth of stuff on top of it, I need to do a little planning in advance this time.
Thanks.
Now that I have found a way to fix the web site I would think that I should have everything ready in a week or two. Of course that could change when I show up for work on Monday after being gone for over 2 weeks.
Yeah, that sounds familiar. Chances are that the page structure on the remote site is mirrored on your local drive. It would be a matter of pointing FileZilla (or your FTP program of choice) to that directory and to the local site. Then you could see pretty quick if they are the same structure. If so, then you could bypass FP and just push the site with FZ...but I understand you just want to get through this last push before you get the new site up and running..
Good luck!
As far as work...yeah I go on Monday too. Been off since the 23rd. Should be interesting!
I noticed in the "Post your Tubelab pictures" thread that you had used a Simple PP board as a PPP monoblock. I was wondering if it would be possible to build an amp with two Simple PP boards in the same configuration to get a stereo amp but using only one shared PT and two OT's, one for each board?
I was just curious if such a thing was possible.
I was just curious if such a thing was possible.
i can offer my services as an inbetween if required. fau upload speeds are a lot higher than even speedy dsl speeds. im only a 15 minute drive away from you. if any big uploads are to be made i certainly wouldnt mind making them from school.
The picture was taken during the experiment that led me to believe that such a thing is indeed possible. I have not done it yet though. The single OPT per channel is a given. I used a single 3300 OHM OPT for that experiment.
The single power transformer is a bit more difficult. When I did the experiment the total current was about 250 mA for a single channel at 60 watts. Assuming a more reasonable power level you would still need 400+ mA at about 400 Volts. This much current would kill a single 5AR4 (especially the new production stuff) so two are needed (one in each board). OK, two 5AR4's. Now we need two 5 volt windings, or one that can handle 4 amps. That (with a 400 mA HV winding is a big transformer. The only one that pops into my head is the One Electron BFT-1. This Big Flippin Transformer weighs 16 pounds and costs $170. That leaves me out. It may be a realistic possibility for some builders (more than one Simple SE builder has used it), but I am still looking for a cheaper alternative. I am thinking an Antek toroid with either solid state rectification, or an added 5 volt winding.
I will get back to this once the manual is done and I finish the two Simple P-P amps that I have already started. I will make an amp in this configuration if it is possible. I have envisioned a rather small cube shaped enclosure, so a small power transformer is a must.
Thanks for the offer, but for now I just start the upload before I go to bed. That way I don't even notice how long it takes. It does seem that My DSL is quite a bit faster than the DSL at my mother in laws house in West Virginia. It costs twice as much, so it should be faster. I went to FAU for my masters degree, but that was about 10 years ago. My daughter went there too.
I sent off an email to AnTek with the basic specs you mentioned above just to get an idea what the cost might be for a toroid like that. Hopefully I will hear back from them shortly.
Is there anything else they would want to know in order to spec this out?
Just trying to get an idea of what is possible (or affordable).
-Steve
Is there anything else they would want to know in order to spec this out?
Just trying to get an idea of what is possible (or affordable).
-Steve
Please post if you get an answer from them. I never have.
I really won't know until I have actually built the amp. The board shown in the picture was a single channel running on my bench power supply. There are a few more steps involved before I can specify a power transformer.
I have a few transformers to try, (including a 4T360) and it really isn't too hard to add your own filament winding to an Antek, or to use a second transformer for the 5 volt filaments.
I have one of those too. I like cheap transformers. I can affort to buy them to play with. I got most of mine when he used to post auctions on Ebay. I placed minimum bids on several at the last minute, and got a fair collection of Anteks.
I get well over 500 volts of B+ when I use the 4TK400 in a Simple SE, so I think that it will blow up any EL84 type tube known to man. The 6.3 volt winding is good for 4 amps. We need to light up 8 EL84's at 3/4 of an amp each plus 2 12AT7's. That means 7 amps of 6.3 volt power!
I have a really nice toroid that I used in a P-P amp about 5 years ago. It powered 4 KT88's to about 50 WPC. I took the amp apart a few years ago thinking I would rebuild it. That never happened. I thought that toroid would be perfect.....until I looked up the current price. I got the first one they ever made, for $100 and I thought that it was too expensive. Now... $263! Nice transformer, but $263? I guess that they really don't want to sell to the DIY market.
Toroidal Rectifier Tube Amplifiers - Toroid: Manufacturer of Power Transformers and Chokes
I will likely spend most of this weekend finishing up the manual. Then I can get back to building some amps. The dual mono SPP is number 2 on my list.
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