tube fanatic

If headroom is your goal, going to 20 watts will only give you a bit over 5db. Since you’re going to incur an expense, I would look at amps in the 40 watt or higher range. Check out the Yaqin amps on Amazon. They offer a lot of value for the money and are popular with users of Klipsch speakers. Maynard

How did you determine the required wattage? If you provide details about your room, listening level, where you sit in relation to the speakers, type of music, etc. it will be easier to provide some guidance. You may need lots more or possibly less power. There is an easy way to make a measurement if you are interested. Maynard

Lots to talk about here. Will comment after mods move this to the tubes section! Happy new year (I hope). Maynard

I am wondering if the virus has now found a home in the squirrel population. Considering that it has affected mink it would not be surprising. https://abc7ny.com/squirrel-attacks-aggressive-squirrels-queens-rego-park-65th-drive-and-fitchett-street/9171481/ Maynard

Approx. 4 wpc SEP using 7695s Maynard

The SuperAmp 2: Maynard

Really? https://www.wsj.com/articles/covid-and-the-new-age-of-censorship-11607381415 And what about the censorship occurring on Facebook, Google, et al? Maynard

Bosco, I enjoy arguing with you! So, you seem to be in favor of cutting off federal and/or state assistance for those who choose not to be vaccinated. Many share your viewpoint. In the supermarket I always see people walking around with a mask beneath their nose, as well as some food preparers. What kind of sanctions would you impose on them? Travis mentioned using drivers license eligibility as being contingent on furnishing proof of vaccination. Do you agree with that too? Will people who have not been vaccinated be required to wear an arm band so they can be avoided? My whole point is that if a person chooses not to receive the vaccine after being educated with the pros and cons (and, yes, there are cons) that should be the end. The NYPD and NYFD is not requiring the vaccine. Should those refusing be fired? And, Billybob, I have found that when such ideas are put forth by those who have the power to make them a reality, we better watch out. I won’t be around the rest of the day, so feel free to criticize! Maynard

I totally agree with you. However, you need to consider the numbers of people who will die from suicide when their only source of income is cut off. Look at the stats on drug overdoses (both legal and illegal) since the pandemic began. How will society deal with the cost of millions more homeless people, or people who can’t afford food, if the government cuts off their income? The philosophy of “get vaccinated or die” does not seem ethical, especially since there is no data on how long vaccine induced immunity will even last or whether the vaccine will prevent people from contracting the virus or spreading it. Maynard

Cutting off SS (or food stamps as some have proposed) from those who refuse vaccination will kill more than the virus. Using the Jacobson smallpox vaccine case from 1905 as the basis for such strong arm tactics is ludicrous imo given that COVID is killing 0.2% to 0.6% of those infected. Smallpox in 1905 killed 30%. A mandate from private industry is one thing, but government doing it is going to be unacceptable to many. Maynard

If you understood how PCR tests work you would understand why Florida and NJ have raised questions and why a test with better specificity would be very helpful. Enough said....... Maynard

When a lab runs a PCR test for coronavirus the number of cycles can greatly influence the result and yield many false positives if cycled too many times. Florida is now requiring labs to report their test cycles. It will be interesting to see if this yields far lower numbers of true positive cases than before. Even NJ has raised some questions about validity. Given that shutdowns are being based on positives as opposed to actual sick people this may get very interesting: https://www.flhealthsource.gov/files/Laboratory-Reporting-CT-Values-12032020.pdf https://www.nj.gov/health/cd/documents/topics/NCOV/APHL-COVID19-Ct-Values.pdf Maynard

Inverterless (or self inverting) push pull amps were quite the rage back in the day. In fact, a guy has been after me to resurrect a low budget version of my “Little Pee-Pee” SIPP (my wife named it and I have never had the nerve to ask about the source of her inspiration...). I am vacillating but may consider it next build season. Maynard

A worse situation was the ubiquitous hot chassis table radios of the 30s through 60s. In spite of that hazard I never heard of anyone even getting a shock from one in spite of many having their backs removed for ventilation, knobs removed for whatever reasons, etc. I am sure things happened but it was seemingly a rare occurrence. Maynard

Separating a p/s from a preamp or amp is different from separating an OPT from the amp chassis. Will you be running a feedback loop from the secondary to the driver? Even if you are not it is usually a good idea to ground the secondary in case there is ever a primary to secondary short (unlikely but possible). Can you post the schematic of the amp? Maynard

What is your goal if switching to tubes? What kind of sound are you looking for? The RF-82s do extremely well in an all tube system. Maynard

I agree with the Mac test clinic impression. It's rare that I like a push-pull amp but this one really impressed me not only on the bench, but listening as well. The synergy with the CWs is something to hear. Eico was always a sleeper brand and didn't get the recognition they deserved. The OPTs on this unit are massive and obviously of top quality. I lived about half an hour from Eico and worked on lots of their stuff in the 60s and it was all excellent. Maynard

Restored Eico HF- 89. Original P/S caps left in place on top to preserve cosmetic appearance. This amp is powering a pair of CWs for the “guy down the road” and provides amazing performance. Maynard

The capacitor former featured here works extremely well. I use it to form new caps prior to installation as well. https://www.rfcafe.com/references/popular-electronics/build-electrolytic-restorer-popular-electronics-october-1970.htm Maynard

A 200V range is too high. Does the meter have a 2v range? Maynard

Two things to try- 1) use an extension cord to plug the amp in someplace else to hear if anything changes. 2) if you have a multimeter, set it to the lowest AC range and clip the leads across the terminals of either speaker and report your reading. Maynard

Chokes and capacitors form a resonant, or tuned, circuit at a particular frequency (depending on value) and exhibit a -3 db point at a particular frequency (the corner frequency). You are familiar with this from speaker crossover networks which provide a chosen corner frequency. In an amp power supply you can inadvertently choose values which have a corner frequency which is much higher than the lowest frequency you want to reproduce. You can demonstrate the effect with this calculator (select solving for frequency and the appropriate units): http://www.1728.org/resfreq.htm Try specifying an inductance of 0.3H and a capacitance of 50 uf (typical lses values as I recall) and you will see that the frequency falls in the low bass area. Compare that with more typical values of, say, 5H and 100 uf. The above is a very diluted explanation, of course, but should help a little. I’ll try to explain a bit about Q when time permits. Maynard

Please describe the sound you are hearing in more detail and if it is from both speakers. Does it change with the setting of the volume control or input selector? If it has a phono input, do you hear the sound with only the turntable connected and nothing else? Maynard

But tubes have so much more charm😁. Admittedly, I don’t agree with Rod on absolutely everything. I am often asked why I bother with tubes given the performance available from SS devices. The only answer I can give is that they attracted me from my first view of glowing filaments when the repairman came over to fix grandma’s console radio when I was 3 years old. We all have our obsessions..... Maynard

We have been exposed to a philosophy of tube amp power supply design here on the forum which advocates very low inductance chokes, very low value filter caps, tube rectifiers, and high ripple. I have expressed my personal disagreement with this philosophy. Here, Rod Elliott explains very clearly (using proven electrical engineering principles) why such designs are inappropriate. Scroll down to the section on power supplies for his explanations: https://sound-au.com/valves/design2.html The discussion is a bit technical, but the conclusions are very easy to understand. Maynard