Fazio Electric  - Page 1
Forum section: electronics / general

author: strawberry
author_rank: Super Contributor
timestamp: December 26, 2021, 06:12:54 am
content: soldering pencil seems a bit too hotESR meter reads 35.9uF

author: mansaxel
author_rank: Super Contributor
timestamp: December 26, 2021, 08:26:31 am
content: The world of guitar amp repair has its fair share of cargo cultism. I think Fazio Electric is a welcome addition, bending the scene towards actual competence. No fuss. Doing what is needed. End of story.

author: Shock
author_rank: Super Contributor
timestamp: December 26, 2021, 12:21:03 pm
content: Colleen has some skills and appears genuine and sincere.

author: mansaxel
author_rank: Super Contributor
timestamp: December 26, 2021, 12:53:10 pm
content: Quote from: Shock on December 26, 2021, 12:21:03 pmWe (or preferably those on that side of the ocean, for reasons of shipping..) oughta do some repair queue cleanout and offer Fazio a Tek tube scope, a 200 type oscillator, and a VTVM, to get the feel of the bench right.In my mind, instruments that perform work are happy instruments. I would argue that the Fazio bench looks to be a wonderful place to age for a mature piece of TE.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 26, 2021, 12:59:24 pm
content: Despite some procedural no-nos here and there, overall her videos are quite alright and have enough editing to keep me engaged without killing too much technical details.

author: Shock
author_rank: Super Contributor
timestamp: December 26, 2021, 02:24:00 pm
content: Quote from: mansaxel on December 26, 2021, 12:53:10 pmShes already doing quite well already on patreon. Probably better off with a modern tube tester if she doesn't own one yet. Kind of you offering up other peoples test gear to support youtubers though.

author: bsfeechannel
author_rank: Super Contributor
timestamp: December 26, 2021, 04:27:55 pm
content: Quote from: rsjsouza on December 26, 2021, 12:59:24 pmExample?

author: mansaxel
author_rank: Super Contributor
timestamp: December 26, 2021, 04:54:30 pm
content: Quote from: Shock on December 26, 2021, 02:24:00 pmTrust me, the prospective donors have got enough.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 26, 2021, 04:57:13 pm
content: Quote from: bsfeechannel on December 26, 2021, 04:27:55 pmSure. In one of her last videos (or perhaps the last), she was repairing an amp sitting upright with all vaccuum tubes fitted. Easily disastrous scenario if the amp topples and breaks them.Also, in the same video she was soldering/desoldering parts on the sockets with the vacuum tubes fitted - the thermal stress of rapidly heating/cooling the socket pins is also propagated to the tube pins, which can create small leaks in the metal/glass junction and reduce the lifespan of the tube. This was a common alert on all the vacuum tube manuals I ever read.There are other minor things such as shotgun replacement of capacitors, etc. but these are more or less justified depending on the conditions.

author: bsfeechannel
author_rank: Super Contributor
timestamp: December 26, 2021, 06:24:46 pm
content: Quote from: rsjsouza on December 26, 2021, 04:57:13 pmIndeed.QuoteWhat is a "shotgun replacement of capacitors"? Did you perhaps mean the use of aheatgunto replace capacitors?

author: mansaxel
author_rank: Super Contributor
timestamp: December 26, 2021, 06:39:36 pm
content: Quote from: rsjsouza on December 26, 2021, 04:57:13 pmI for one think -- while not being a confessed shotgunner myself -- that replacing caps is a refreshing down-to-earth attitude compared to the mythicism surrounding old leaky crapacitors; a bad offspring of the tube vulture vandalism.It is the circuit that does the sound, not the age of the crapacitor. Any fool can swap in a NOS cap. Hardly any fool can design an amp. This borders on audiophoolery practices, which a lot of the time is "We can't change what's important (the acoustics of the room) so we place the speaker cables on small supports of special wenge and pockenholz construction and think that it's going to make our horrible room sound better."There is one case of "worse is better", though, that bears mentioning:Many years ago, I worked at a place where we were tasked with repairing theatrical dimmer packs, the kind where there's a 30A input, and 6 5A circuits controlled by a 0-10V signal per circuit. The triac would fail, and sometimes take the trig optocoupler and an adjacent resistor with it. We looked up the values, got new parts, slapped it together, and out the door. Tested, working.It came back, a bit too often, with the resistor fried. Ok, higher wattage resistor in, out the door, next!And it came back again. Same fault. It turns out that the original resistor was carbon comp. We'd fitted metal film. According to the manufacturer, the circuit was marginal enough that there were latent oscillations in it that only were tamed if the resistor was carbon comp. If a "better" metal film resistor got replaced, the oscillations went on a rampage.

author: nctnico
author_rank: Super Contributor
timestamp: December 26, 2021, 07:35:50 pm
content: Quote from: rsjsouza on December 26, 2021, 04:57:13 pmI noted the can of Deoxit contact cleaner which was used tocleandestroy the potmeters on a unitA real repair would be to replace the potmeters with new high quality ones. Or just leave the potmeters as-is if they are fine. If it ain't broken don't ruin it.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 26, 2021, 08:53:19 pm
content: Quote from: bsfeechannel on December 26, 2021, 06:24:46 pmAh, the term "shotgun" (espingarda) alludes to the very wide blast area of a shot that comes from a shotgun and is usually used when someone in repair goes and replacesallparts regardless of their current state. As you can imagine, this is very common with capacitors.I, for one, always try to avoid doing this whenever faced with an equipment repair. Obviously that, depending on the complexity of the repair, importance of equipment or obvious recurring faults, this is the best approach.Quote from: mansaxel on December 26, 2021, 06:39:36 pmI don't believe in the capacitor voodoo as well - I just hate replacing parts with no justification.Throughout the years, however, I was faced with several scenarios where rows of capacitors were suspicious enough to warrant a shotgun replacement, such as my grandparents' 1946 Philips radio that had several paper-oil capacitors replaced in the early 1980s by my dad. This year I put it back on my table to do a renovation and all of them showed higher leakage than an original tar capacitor that he forgot to replace back then. I can't help but wonder if all these indeed needed replacement back then, but that is now history. Not to mention that, when a tar capacitor goes "kaboom", it makes quite a mess (just like the box Rifa capacitors).Quote from: nctnico on December 26, 2021, 07:35:50 pmAlthough Deoxit is less crap than WD40 (commonly used by inexperienced people), some of these pots are unfortunately irreplaceable or their purchase is absurdly costly, making people take those desperate measures. Although Caig has some recommendations for potentiometer maintenance - I am not sure what product she used, though.

author: nctnico
author_rank: Super Contributor
timestamp: December 26, 2021, 09:00:41 pm
content: Quote from: rsjsouza on December 26, 2021, 08:53:19 pmAccording to my experience using 'contact cleaner' always makes the situation worse in the long run. The oil turns dust into a fine grinding paste and the acids will slowly corrode everything away. The worst part is that wires will wick it to other places causing havoc. My firm believe is that contact cleaner is great to make a piece of equipment work for another day before you throw it into the trash. Over the years I have seen enough examples of equipment which would be perfectly restorable if some idiot didn't use contact cleaner on it in the past.If you really want to clean a contact or potmeter, take it apart and use alcohol to get rid of dust & oil and re-apply acid-free grease where necessary.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 26, 2021, 09:29:34 pm
content: Quote from: nctnico on December 26, 2021, 09:00:41 pmIndeed that is the best repair method.

author: Johnny10
author_rank: Frequent Contributor
timestamp: December 26, 2021, 10:00:57 pm
content: That's interesting that you say this about Caig Deoxit. All the tube amplifier repair gurus recommend using D50 or Fader F-Series Lube to correct scratchy pots.I have used it on my 1960's era Stromberg Carlson Tube amps with lasting (many years) effect.But I am willing to rethink this if you have evidence to the contrary.I am going to be repairing a couple of 1970's Mcintosh transistor amps that are beginning to have crackly potentiometer issues.Noting that these are mostly unobtainable parts.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 26, 2021, 10:36:33 pm
content: That's the most elaborate nail painting I have seen on an electronics tech. It's already showing signs of wear which explains why it's more common with software engineers.

author: nctnico
author_rank: Super Contributor
timestamp: December 27, 2021, 12:56:13 am
content: Quote from: Johnny10 on December 26, 2021, 10:00:57 pmUnobtainable in what way? If it is just the value, you can put a resistor in parallel to get to the original value give or take some non-linearity but that is likely dwarfed by the tolerances in the rest of the circuit.

author: floobydust
author_rank: Super Contributor
timestamp: December 27, 2021, 01:12:46 am
content: Quote from: nctnico on December 26, 2021, 07:35:50 pmDeOxit works fine on switches and potentiometers. It's kind of designed for that. Where are you getting this "destroy" bullshit from?Worst I've seen are cleaners loaded with petroleum-based oil which is terrible on phenolic. Cleaning out the old lube etc. without removing oxide from the wiper leaves you will a scratch pot still.Replacing the potentiometers on vintage gear is difficult (high ohmic value, taps etc.) and expensive they easily run >$15 a piece, and don't even mention putting in cheap chinese parts.I shotgun (outright replace all) electrolytic capacitors at the 40 year old mark, good luck to all who think they are fine for another 20.

author: Johnny10
author_rank: Frequent Contributor
timestamp: December 27, 2021, 01:50:26 am
content: Do a little research on vintage Hi-Fi amplifiers and preamps.2-6 thousand dollars is not uncommon.Where do you get original type parts for reasonable dollars.Volume pots for my unit running close to 90 dollars.Guess shouldn't have said unobtainium after a bit more searching.The question was, is Deoxit going to be destructive in some way?

author: floobydust
author_rank: Super Contributor
timestamp: December 27, 2021, 04:01:42 am
content: I didn't hear reasoning or experience or science for condemning DeoxIT.Caig Laboratorieshas gone way overboard with their marketing, confusion, redundant products etc. It's gross trying to pick one of their products. I hate it. They dumb it down and make a product for every application and component imaginable in order to sell more more more.There must be a dozen threads on EEVblog about servicing potentiometers and rotary switches. Everything from WD-40 fanboys to worse. It starts a Holy War everytime.There are cleaners, which are solvents to flush out dirt and old lube.There are contact enhancers, which are PPE and anti-oxidizers.There are lubricants, which are grease or oil. Silicone or petroleum based. Some have teflon particles added.If people could understand the three essentials- and that no products do it all. We're just lazy and want to use a spray. Some ingredients are bad with certain materials. I review the MSDS for chemical composition and use that to figure it out.I found DeoxIT Fader Lube F5 is good at the contact surface, but it's not a lubricant. The shaft is not looked after, likely wear fast now and feel dry. I sprayed some F5 on a paper towel and mirror only to find all except the PPE had evaporated in one day. I would say it's useless as a mech lubricant, and only recently they announced DeoxIT greases like FaderGrease (silicone) but all others use lithium and not suitable for your multimeter rotary switch IMHO. That's where you need both a lube and contact enhancement.In the old days I was in there with grease on pot's mech, you had to do that after the clean and contact enhance.Taking apart potentiometers to clean them is just hard due to the crimps and vintage gear i.e. 1950's too fragile sometimes for it.

author: bsfeechannel
author_rank: Super Contributor
timestamp: December 27, 2021, 05:16:19 am
content: Quote from: rsjsouza on December 26, 2021, 08:53:19 pmAh, OK. Now I understand what you mean by that. Yes, but for those 40+ year old amps, as others pointed out, there's no point in testing capacitors one by one to see if it is worth replacing them. There's almost a consensus among guitar amp repair people that they should all be changed out. Sometimes their clients insist on preserving at least the tone capacitors because they believe that that's where the "mojo" is, but leaky coupling caps and dried-out filter caps all go mercilessly. Their replacements are cheap these days and the presence of the old ones can compromise expensive parts like the output tubes, the rectifier tube, the power transformer or the output transformer. No musician wants that.

author: Shock
author_rank: Super Contributor
timestamp: December 27, 2021, 07:40:11 am
content: If the amp is cheap and the owner just wants it fixed and reliable, you're not going to be dismantling pots and stuffing caps. There is a large difference between a quick repair and a vintage accurate restoration.Fader lube (F100L) is for carbon, the plain red Deoxit (D100L) for oxidized metal, Deoxit Gold (G100L) is for gold.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 27, 2021, 12:05:33 pm
content: Quote from: floobydust on December 27, 2021, 04:01:42 amAnd these are two of the issues with this whole subject; there is a lot of anecdotal evidence with varying degrees of reporting quality, but marketing does not help as they are trying to oversell. In general, in a repair one might not have the history of the prior "fix", only the final result of the techniques and compare to one's own experiences or knowledge about what the product did in a prior attempt. Internet helps with that, but only to a certain extent as it is hard to separate the wheat from the chaff.A single product also does not do it all, thus the best technique (again, in my experience) would be to clean the part piece by piece and not as a whole using one or more sprays. Obviously that is not possible in all scenarios. Back in my early days I too had applied WD40 to a variety of inappropriate materials and purposes, allured by the marketing surrounding this product, only to find a worse situation only months later. Although not DeoxIT, I have seen other sprays and products (teflon spray, Singer oil, lithium grease, etc.) applied with varying degrees of results.Quote from: bsfeechannel on December 27, 2021, 05:16:19 amIn my experience, musicians want different things and not necessarily the technically superior solution - it is not uncommon they want to preserve the original appearance as much as possible, despite the fact the parts are enclosed under the chassis. For that particular aspect, preserving the original capacitors as much as possible can save some headaches (and create some, of course). Again, it is always a balance between what is needed and what is wanted (and obviously how much $$$ one wants to spend)Quote from: Shock on December 27, 2021, 07:40:11 amFully agree; however, thereliablepart is what is always on the table when lubricants for pots are discussed. floobydust's post encompasses well what a potentiometer requires overall and your three options are good for the track, not for the shaft.

author: Shock
author_rank: Super Contributor
timestamp: December 27, 2021, 04:53:21 pm
content: I wasn't replying to Floobs post, just mentioning what Deoxit product is for which contact type. If you have dry lubricant on the shaft as long as it's not super contaminated or damaged there are a few ways to free it up (without opening). As I said, the customers budget often dictates these things.

author: strawberry
author_rank: Super Contributor
timestamp: December 29, 2021, 04:35:54 pm
content: soldering station cranked up to 450C

author: mansaxel
author_rank: Super Contributor
timestamp: December 29, 2021, 05:54:24 pm
content: Quote from: strawberry on December 29, 2021, 04:35:54 pmIf you know what you are doing and are fast, that's going to go just fine. If you're going to linger on delicate components, not so much. There is a bit of personal taste to this, and there's no doubt that the designated temperature is going to be the safe bet, but skilled people can bend the rules pretty much and still produce similar results. Especially in things like point-to-point wiring.

author: Shock
author_rank: Super Contributor
timestamp: December 29, 2021, 06:32:20 pm
content: It's only a small tip, she probably has to crank it when desoldering wires from the chassis. Towards the end of the video it looks lower anyway.

author: strawberry
author_rank: Super Contributor
timestamp: December 29, 2021, 11:11:02 pm
content: solder gets dull and flux is evaporating at first touch.faster soldering iron wearoutif component lead knot not want to giveup then crank up temperature, it is some psychological emotional stuff I dont believebetter suck solder off then untangle using sharp pliers

author: floobydust
author_rank: Super Contributor
timestamp: December 30, 2021, 01:53:11 am
content: I looked and her soldering style/technique is to be quick, she's fast. So the iron needs to be quite hot for that, with large through-hole parts.I've found that works fine, contact time is brief, but it does oxidize the tip faster and wreck (melt/overheat) things if you ever need to stay on the joint for more than a few seconds.Everyone has their own style. I teach noob engineers to use a lower iron temp and simply wait a couple seconds for the joint to melt. Some of them have no patience though.You can always do something better, find faults in others. I don't see how criticizing the repair video is constructive

author: vk6zgo
author_rank: Super Contributor
timestamp: December 30, 2021, 02:16:29 am
content: Quote from: rsjsouza on December 26, 2021, 04:57:13 pmIf so, it was the most neglected alert in the real world----nobody had the time to pull all the tubes when equipment was needed "yesterday"!The thermal stress upon the pins using modern irons is also minimal compared to that from the irons we used back in the day.QuoteExperience, along with urgency of return to service is usually the arbiter of whether such actions are necessary.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 30, 2021, 12:10:58 pm
content: Surely these aspects would be much less relevant back then when professional repair was mainstream and vacuum tubes could be found anywhere, but you can't deny they will save you from big headaches especially in today's day and age. Also, the videos give the opposite impression of a "production line repair" - they are quite detailed and caring instead, thus the five seconds per tube removed is rarely an impediment.I did a few non-professional repairs back in the 1980s and, apart from the manuals I had read, these were also rules backed by the experience of some of the TV technicians I knew and read about at the time - some of the vacuum tubes were already expensive back then (not the PL36s and PY88s, but especially the big PL509s or PY500s of the big 26'' TVs) and minimizing these risks was already wise.Overall, as I said before, the videos are entertaining and useful and nobody (including me) is perfect but we all have to be open-minded to improve, even if we have been doing this for 40, 50 years.