A few questions since i happened to fall into some spare parts.
I happened to fall into 2 opt's that are 8k and 4ohm. My speaker selection is about 50/50 4ohm/8ohm. Is it safe to put a 8ohm on the 4 ohm taps with this design?
the opt's have ul taps, they would just go strait to pin 9, or should i pop in a 100ohm/2w resistor like in pentode mode?
what b+ are we shooting for for the preamp and output tubes?
Should i do a stock build or as any real mods been done in the last year? I see there is zero sand in this design, unlike the baby huey or red light district el84pp units.
I happened to fall into 2 opt's that are 8k and 4ohm. My speaker selection is about 50/50 4ohm/8ohm. Is it safe to put a 8ohm on the 4 ohm taps with this design?
the opt's have ul taps, they would just go strait to pin 9, or should i pop in a 100ohm/2w resistor like in pentode mode?
what b+ are we shooting for for the preamp and output tubes?
Should i do a stock build or as any real mods been done in the last year? I see there is zero sand in this design, unlike the baby huey or red light district el84pp units.
Aim for a B+ around 320V. You will find in the thread here a few users had an issue with B+ a bit high for the brand of tubes they were using. Very few mods have been documented, maybe one or two. Seems to work great out of the box!
More tranny info here.
More tranny info here.
George did get back to me with a msg yesterday.
Very long hours at work....no time for emails about Tubelab most days.
Boards are still available and he's going to look for parts on hand to possibly put some kits together.
So I've ordered some iron and started thinking about a case/chassis.
Very long hours at work....no time for emails about Tubelab most days.
Boards are still available and he's going to look for parts on hand to possibly put some kits together.
So I've ordered some iron and started thinking about a case/chassis.
I sent a couple of emails, 2-3 days apart with no answer. So I sent George a message (pm) here and got an answer back with info, and a commitment to get back to me yesterday on the parts kit availability. He had received & read the emails, but was unable to answer from work, apparently.
John
Yes, Russ is right. We used to work for the same company until a few "activist shareholders" demanded the breaking up of the company. So now we work for two different companies. In our facility they put up walls and we aren't allowed to talk to people from the "other side".
The policy for "secondary employment" has recently been restated, and at least one person was made a public example by being fired. All company provided equipment including computers and phones are monitored for violation. I got home from work tonight at about 7:30 PM so I basically can't answer email during weekdays.
To make matters worse this forum has been classified as a "sports and entertainment site", which is not strictly forbidden but usage is logged and your management gets a printout of your computer and telephone usage every month. I have seen my printout and my biggest usage is Google, Digikey, Mouser, and all the usual distributors followed by the IC makers like TI and Analog Devices (all job related stuff). This forum was in the top 10 but not standing out, and I intend to keep it that way.
I use a smart phone to answer most forum posts during the day. So it is unfortunate that I usually must wait until the weekend to answer Tubelab email. Sometimes there is more email than I can possibly answer in a whole weekend, which doesn't leave much time for life.....
My wife, Sherri and I started Tubelab Inc. over 5 years ago. She did all the organizing, shipping, inventory, and administration. I did all the technical stuff. There were about 6 tube head engineers at work, both HiFi and guitar amp guys, that helped build prototypes, offered advice and tested and tortured my stuff. This all worked out pretty well. Since then ALL of the other engineers have been laid off and all but one have left the area to find work. The one that still lives here works for the competition and we aren't allowed to associate with each other.
About 4 years ago Sherri's step father died of cancer. Shortly thereafter her mother was diagnosed with Melanoma, a particularly nasty form of skin cancer that has recently claimed another forum member and one of my previous bosses. The usual life expectancy from time of diagnosis is 6 months, which was the case with the two people that I mentioned and Sherris mother was headed in the same direction.
We agreed that Sherri would spend as much of her time as possible with her mother in her final days. Sherri left her job here and began travelling back and forth to her mothers place in rural West Virginia. Conventional surgery, chemo and radiation therapy failed to slow the cancer. About 3 years ago Sherri's mom offered herself as a human guinnea pig at the University of Pittsburgh and they found a course of treatment that stopped, but couldn't cure the cancer. The situation was improving and Sherri began spending more time here at home, flying to Pittsburgh only for the hospital stays.
When the economy tanked the plug was pulled on the clinical trial that helped keep her mom alive. This resulted in Sherri spending a lot of time in West Virginia. She was home for 44 days last year and only 9 this year, when my mom died. I was spending a lot of time up there as well. Sherri's mom passed away about a month ago.
Things should slowly return to normal over the next several months. We will both be travelling back and forth for a while to clean up a zillion loose ends. There are two houses, a ton of stuff and several relatives that want things, with no will to sort it all out. Sherri should return home for the first time in 6 months next week. Right now I have tubes and parts in every room of the house and I have some serious cleaning up to do.
Sorry for the dissertation but maybe it helps to explain the situation. I have always kept a good stock of all 3 boards. They are on a shelf above the computer, and even I can handle shipping them. We decided to start selling the parts kits as the Simple P-P was being designed. That made it easy since we ordered several sets of all the parts. Sherri made up 10 kits which were sold. The last one was sold late last year and until now no one has expressed an interest. My inventory says I have all of the parts to make at least 10 more sets for the Simple P-P. I just don't quite know where everything is, and Sherri doesn't remember either.
I have 100 of each resistor from that original kit order. I have the resistor box, and the tube sockets. I am still missing some capacitors, but they are in this house somewhere. All new kits will have the same parts.
We were in the process of collecting the parts for SSE kits but that never got finished before Sherri had to leave. We will finish those up as time permits.
I will not be home Tuesday and Thursday evening this week, so it might be next weekend before I can get into the stuff boxed up in the back room. Sorry for the slow replies, but it is the best that I can do right now.
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My condolences to all your family as well.
I am new to this and I have been looking for a valve amp project, and after all of my looking around I have come to conclusion that your amps are the best.
When you are able to continue with Tubelab I would be very interested in one of your kits or if not a kit, the purchase of some boards with help in what components etc for use in the UK.
I am new to this and I have been looking for a valve amp project, and after all of my looking around I have come to conclusion that your amps are the best.
When you are able to continue with Tubelab I would be very interested in one of your kits or if not a kit, the purchase of some boards with help in what components etc for use in the UK.
Welcome to diyaudio!
The tubelab.com site may not show the Simple PP board as available , but is for the same price as the others. There are also two SE boards , the Simple and the DHT one. Now you have to decide between SE or PP. More power from simple PP which might suit more speakers and EL84's do sound really nice. Lots of info on that site and this form.
The tubelab.com site may not show the Simple PP board as available , but is for the same price as the others. There are also two SE boards , the Simple and the DHT one. Now you have to decide between SE or PP. More power from simple PP which might suit more speakers and EL84's do sound really nice. Lots of info on that site and this form.
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I read somewhere you could try the 12AV7/5965 as a sub for 12AU7. 12BH7A & ECC99 would be better sonically than 12AU7 and plug in a circuit designed for the latter, but because of lesser drive you would probably have to put 12AX7 or slightly lesser gain 5751 in front of it like like the diytube ST-35.
http://diytube.com/phpBB2/viewtopic.php?t=837
Edcor has a new 25W 8K Output Transformer that has 23% UL taps more suitable to EL84/6BQ5 than 40%.
EDCOR Electronics Corporation. CXPP25-MS-8K/23%
http://diytube.com/phpBB2/viewtopic.php?t=837
Edcor has a new 25W 8K Output Transformer that has 23% UL taps more suitable to EL84/6BQ5 than 40%.
EDCOR Electronics Corporation. CXPP25-MS-8K/23%
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