Electronics! Falling into the geek rabbit hole.

I've considered this 4 channel that mounts piggy back on the head unit https://www.crutchfield.com/p_500KTA....html?tp=35782

Then I return to trying to keep the total spend as low as possible. What if I just run my old alpine amp to the front components I put in?

I'd probably still throw the 6x9's in the back since I have them and it's beyond the return window with Crutchfield. The rattles are constant and ever changing, today it might be silverware in a drawer, tomorrow it could be the camp stove got stored up against a folding chair. Never ends

Looks like powered subs are a more economical way to go than separate amp/box etc, guessing sound isn't as good but this is a rolling metal box.

Could probably find room for this to get a little more punch https://www.crutchfield.com/p_777B10...AS.html?tp=114

Long shot here: Covid/WFH finally forced me to pull out my old stereo system(s) and vinyl from under the basement stairs. Have two Denon receivers and two Harmon Kardon (460 and 330) hooked up to some Boston Acoustic VR965s and Klipsch Model 4s. Sound is provided by a Denon CD player and a BIC 980 turntable. The pride of my setup would be a Denon DP-57L turntable but unfortunately the counterweight shaft was bent years ago during a cross-town move. I've tried every local Mpls/St Paul) audio repair store but none of them want to take it on after I share this: https://www.vinylengine.com/turntabl...ic.php?t=98815. I have never possessed the skill set to take on the project myself but most of you here seem incredibly able. So anyone relatively local to the Twin Cities metro who would like to make a couple hundred $$? (I DM'd the guy from vinylengine and he estimates it takes around 3 hours and I had a $150-200 quote from a local guy before he bailed). Any suggestions would be much appreciated and your pardon if this is not apropos the OP

Sounds doable... But I'm in salt lake.

Speaking of denon stuff, I got a new toy today. Denon pra-1100. I'm a sucker for preamps, cause they are cool, fun, and not very expensive. This one is matching cosmetics to my amp, so I figured why not? Looks sharp, sounds great. Will have to give it a little extended listening later on, but a quick jam of MMW's bubblehouse shows great bass, nice imaging, nice cymbals. Sounded good. I like the clean minimalist look with the tone, loudness, source direct phono selection controls all hidden behind the fold down front panel.

Still loving the bang and Olufsen speakers.

Edit, someone should really dust around this house...Attachment 375173

sent from Utah.

I also snagged an entirely unneeded adcom gfa 5006. 50x6, or 175x3. Nelson pass design I think? Or I read someone else might think that? More research needed. Supposedly has a bad channel. I may fix, or I may gut it. I'm waiting for the newest version of the honey badger to drop over at diyaudio, aka the wolverine. This box, transformer, and heat sink would make a very nice 3ch wolverine amp.Attachment 375174

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Im going to put a plug in for a maggot owned/designed company. Thom is a class act and prob too modest to pump his wares on the forum but if its not the highest of high end turntables, cables, etc i dont know what is. Im sure the vinylfiles would dig this stuff. Its from the future for sure

https://galibierdesign.com/Attachment 375175

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I've been on the lookout for a 555, supposedly a great amp if you can find one.

That turntable is something else. Gonna have to research his stuff. Looks cool. Just poked around the music section of galibier page, badass. Stuff is art that plays music. Amazing stuff.

Yeah, the 555 is supposed to be a hero of an amp. That one actually is a Pass design. They have been my radar for a while, but not found one at a price I like.

sent from Utah.

Gotta love the easy ones. The adcom indeed had one bad channel. Offset looked ok across all 6 channels, but when I passed a signal through, channel 4 was severely clipping on the positive side only, but if I turned the signal power down, it came back into shape. So that gave me hints on where to looked. Pulled the amp board out, and sure enough, the driver transistor for the output on the positive side has a broken solder joint on the emitter. So, resolder, test, bingo. Fixed.
Anybody want a nice adcom 6 channel amplifier?
Attachment 375213Attachment 375214

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Quote:

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Originally Posted by grinch

Im going to put a plug in for a maggot owned/designed company. Thom is a class act and prob too modest to pump his wares on the forum but if its not the highest of high end turntables, cables, etc i dont know what is. Im sure the vinylfiles would dig this stuff. Its from the future for sure

https://galibierdesign.com/Attachment 375175

Sent from my SM-G950W using TGR Forums mobile app

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Thom is a fucking class act for sure. He's operating on a whole different level - lightyears ahead of even his competition - but he still takes the time to chat with me and answer VERY basic questions about amp choice, amp design, etc. No condescension, no pretense, just super helpful advice while meeting me at my level. I would love to listen to one of his turntables at some point in time, I have ZERO doubt that it would be the pinnacle of my audiophile experience.

Quote:

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Originally Posted by tgapp

Thom is a fucking class act for sure. He's operating on a whole different level - lightyears ahead of even his competition - but he still takes the time to chat with me and answer VERY basic questions about amp choice, amp design, etc. No condescension, no pretense, just super helpful advice while meeting me at my level. I would love to listen to one of his turntables at some point in time, I have ZERO doubt that it would be the pinnacle of my audiophile experience.

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Yes! Every bit of that. He's helped me a bunch with my ski fixes despite me being slow on the uptake on a lot of his fix it tricks. He builds tons of cool shit. I really want to hear one of these turntable systems too. When your cables are fabric wrapped instead of rubber for better sound, you know this stuff is striving for the cleanest of clean sound. Never heard of that.Some good reads on the site. Amazing level of detail and tolerances

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Well, this giant old Rotel is back on my radar. It's been sitting for months while I messed around with other stuff. Has a bad channel passing 95v DC to the output. I have replaced a few suspect parts, and put it back together, and tested it with my bench power supply at 25v+- rails, and it appears to be on its way to being fixed. It passes a clean signal and amplifies. Bias adjusts properly, but DC offset does not. We're off to idaho, but I'll have to get back at it when I get home. This thing is a beast of an amp, 400wpc @8ohms, 700wpc @4ohms, and supposedly capable of driving down to 2ohms for short periods. True dual mono design with huge toroidal transformers. Weighs 85lbs.
What am I going to do with it? No idea.Attachment 375886Attachment 375888

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Well that failed miserably. Amp had tested good at lower voltage. I had replaced two output transistors with ones from eBay as all reputable distributors are out and device is obsolete and discontinued. Must have been fakes. Amp lasted about 10 seconds before the outputs failed. Gonna have to figure something else out. GRRR.

But... My denon preamp has been acting up, so into the garage! Cracked solder joints at the rca terminals, and dirty pots. Deoxit on the pots and switches. Reflow all rca solder joints. Yanked the 4 470uf power supply filter caps, and replaced with 2 1200uf caps, so 2400uf total capacitance up from 1880uf. I do like to boost power supply capacitance in my preamps, but not by huge amounts, just a bit, 20-30%. Pre amp is MUCH happier now. Good deep soundstage, speakers sort of melt away, and the sound just emanates into the room. Very nice. Bass is much improved. Need to do more listening, but it's pretty good right now. Blasted some tunes this afternoon while the wife and kids were out. Beastie boys, MMW, cake, powerful sound. Highs are not as sweet as with the holman, so I may do a little digging around the circuit and replace a few more aged caps from the signal path. It's a nice unit though, regulated supply looks a bit like higher end nakamichi pre amp power supplies. This unit is superior to my past denon pra 1500. Not sure if it tops the holman yet. Attachment 376284Attachment 376285

sent from Utah.

New parts for a proper power supply for my Rotel/gb150 amp. My own pcb.
So pretty. 48000uf of capacitance.
Attachment 376298Attachment 376299Attachment 376300

sent from Utah.

Made a mounting platform panel for all my goodies to go in my Rotel test bed gb150d amp. The unbuilt pcb is a buffer circuit of my own design. It's nice to have a big platform with lots of room to put shit wherever I want.
Adding the buffer will ensure that any source I hook up can drive the amp with authority the buffer power supply and transistors will provide ample current to drive the amp so I don't need to and rely on current from the source to drive the amp. Attachment 376429Attachment 376430

sent from Utah.

When are you going to hop us up a D/A converter, BB? Or a tube amp/pre?

Attachment 376475

Attachment 376474

Haha, um... I'm just a noob. I do really like the sound from this gb150d though. It's a mosfet a.mp rather than a bit like the honey Badgers... Does that count?
I'm starting to think about about amp build, with a clean new case, all new parts, none of this recycle broken stuff I come across. If I can make a nice looking basic 100w amp. And make it a beauty, I'll sign you up for one. Looking at building the Nelson Pass ab100. It is a bjt (bipolar junction transistor) based amp. I am getting better at building stuff... maybe I research building a tube amp.

sent from Utah.

Dupe...

I'm using a old Sony 507es cd player (refreshed) a Sony es tuner (beat out the nakamichi tuner handily). I have been running them through a apt holman preamp for the last 6mo, and just got a denon pra1100 preamp recently, and it is in rotation right now. Honey badger amp provides the juice. I also use an older jvc turntable. Both preamps have adjustments for mc mm and different capacitive loading.
i don't apply any room correction eq. I have messed around with it a little bit, but my speaker location is pretty good for these big guys, and it always seems to sound best with all tone controls bypassed, at quieter levels I'll adjust up the bass a little bit.

As for the tubes, I think they basily serve the same purpose as solid state transistors. And I would say, that using the same transistor in different circuits will result in different sound. I imagine the same can be said of tubes, a great tube in a poorly designed or executed circuit will not sound as good as the same tube in a better circuit.
So, what's the point of this post? I'm, not sure. I'd like to learn more about tubes, but the focus has been on transistor based stuff.

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I have a buddy here in town who is into tubes, I borrowed a couple of his Wurlitzer mono amps. They sounded pretty good, definitely had a warm sound to them. I'm not knocking tubes, but the notion that the same tube will sound different in different circuits is a fact. Same goes for transistors. If you reach back to the first few posts I made, I got started down this path by fixing an old car amp I thought was cool, mainly because I like fixing stuff, (see the wrenching thread I started). I thought the amp was fun to diagnose and fix, and I like learning new things. So I built a small basic amp on a breadboard with my kid. That was fun. That's when I started the thread, to see if anyone else had fun tinkering with this stuff.
I also like buying and selling stuff. Cars, stereos, it's fun. My Sony CD player may not sound like the end all be all, but I like putting on an album, and they sound great through this player. I've gone through many cd players, and since this one came in to the house, it has ruled them all. The older es stuff is known to be very nice quality, and when I find a better one (that doesn't cost $1000) it will takes its place.
I don't have any Bluetooth or streaming to my main system, it is fm, cd, and records. This particular amp is going to have Bluetooth because my wife wants to use her phone to play music. Maybe I'll put it in the kitchen. But it also drives the big b and o speakers nicely and sounds great. And with this unit, I am learning about grounding schemes for integrating different circuits (electronics). It is also good platform with the large mounting panel for testing stuff out, sort of a development mule. I did my first Arduino project in this amp, and the Arduino controls the display and input switching (coding and electronics). And it works, and doesn't inject any noise into the audio circuitry. I'm working on stuffing the board for my own design buffer circuit (electronics) to test in this amp. It is an electronics learning playground. I have a copy of Bob cordell's amplifier book that goes into tons of detail. I'm having a tough time getting into it. I've learned how to use fusion360 cad so I could make my own circuit boards (electronics). So from fixing a broken car amp, to designing and implementing my own stuff, even at a rudimentary level, the rabbit hole has proven to be pretty deep.
I like music, and I like sitting back and listening to it as much as I can. Listening on things that I made is satisfying, and yeah, that $7500 McIntosh tube amp probably sounds better than my hacked honey badger. But my honey badger beat out a several thousand dollar Krell amp.
I have probably 200 records, some in better shape than others, and hundreds of CDs. I like the ritual of loading a record or cd and listening to a whole album. I've had Krell amps, Parasound amps, hafler amps, and the honey badger has bested them all in my system. I've had psb towers, Canton (still have those) Polk, Boston speakers, some higher end than others, (cantons are nice) and the b and o blow everything away to date. Contemplating picking up some snells, but we need plane tickets back east.
This thread, yeah, I use it as sort of a blog. There are others here that know more, but I knew nothing a year and a half ago. But this thread is also used as a chat about different gear people have.
As for tubes being the end all be all, when a designer is working on an amp that is going to retail for $10k, choosing bjts or mosfets instead of tubes is not a cost driven concern.


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You are welcome to stop by for a drink anytime and check out the system for yourself.

Just remembered, re room compensation and alignment, I have a 8ch zapco dsp in my car. And cars are fucked up speaker environments, the benefits of being able to tweak the time alignment settings, eq, etc has a much greater impact in the car than I was able to see by messing around with eq in my main setup. A couple choice placed acoustic panels on the wall behind the mains would probably help, but that ain't gonna fly with the missus. Compromises must be made.

Post up your tubes...

sent from Utah.

As far as eq and room compensation setup goes, If you have pretty good speaker placement for your space and not a lot of acoustic room issues, you should be able to run with a minimum of eq added in. A properly designed amplifier (as well as other pieces in the signal chain) should have a pretty flat response curve from 20hz to 20 or 30khz, as that is basically the range of human audible frequencies. With good room acoustics, speaker placement and properly designed gear, minimum eq should be needed, and can best be eliminated. Any unnecessary analog to digital and back to analog conversion should be avoided, (so no dsp) and removing tone control pots extra tone control circutiry and sliders (slider graphic equalizers) should also be removed if possible. They are all possible sources of distortion and signal degradation, again quality of circuit design and quality of execution matter. A lot of the higher end stuff, tube or solid state eschew tone controls completely. Even the McIntosh c70 preamp has very basic bass and treble tone controls, with the option to bypass completely, and they would probably roll over in their graves if they caught you inserted an equalizer between the pre and the amp. I've played with pink noise generators and spectrum analyzers to check for peaks and valleys. It's fun. If an amp or other piece in the signal chain, cd player, preamp, etc, is introduced and requires equalization to adjust for response that is not linear, I think the circuitry has issues. This is frequently the case in older gear where electrolytic capacitors drying out has resulting in drifting capacitance values.
In tube gear, you need to be careful rolling tubes, as they likely need to be matched sets to ensure best operation. So if you are swapping tubes out of a 7 tube amp, you need to figure out which pairs need to be matched, and instead of buying a pair, you probably need to buy 10 and find the best matching pair. My gb150d amp for example requires two pairs of very closely matched mosfets at the output, as well as closely matched transistors at the input stage, per channel. Again, whether it's tubes or transistors, a quality design circuit with quality execution is what makes something great, not just quality parts.

The rabbit hole is deep as I'm finding. At the end of the day, the goal is something that is fun to listen to, non fatiqueing, and gives you enjoyment when you sit back, crank it up, forget about the gear and just enjoy the music.

One of the next steps I want to take is making proper measurements of noise and distortion of the amps and circuits I build.

Here is my buffer pcb built up. Based on an apt holman design, it is 2 channel, and presents an easy to drive load to the source while providing plenty of juice to drive the amp. I'll try to test it tonight on the bench before installing in the gb150d test mule. Attachment 376593

sent from Utah.

I don't know what you are going on about. I use Panasonic caps, and and yageo, xicon or koa resistors. I try to use decent stuff and not waste my money on snake oil.
The monoprice amp you posted a link to earlier was panned as an amplifier. I don't think rolling new tubes in there will solve the issues. From audiosciencereview.com
"Conclusions
The monoprice hybrid tube amplifier nails the looks and aesthetics. The mechanical engineer and material procurement people deserve an A. The electronics designer now, gets a failing grade if he though this is a hi-fi product. Poor guy though was likely told to build this for nothing.

Congratulations are in order then for Monoprice to have produced probably the most faulty, and poorly measuring audio product I have tested to date. This would be good as a conversation piece on your desk and that is about it.

NOT recommended."

As for my buffer, I'm not reengineering the most well thought out amp of all time. I'm using a basic buffer used in that design, and not dissimilar from other buffer designs. I like the holman preamp, and while repairing it, got to know the schematic. I'm changing certain values in components because it is doing a slightly different job in my case. Can I drop hundreds on it with fancy large film caps? yep, but I'd like to get it working first. I made a mistake on my pcb using the incorrect model for a voltage regulator in the diagram that resulted in my pinouts being crossed. Beginner pcb design mistake. I'm just doing this because I like learning new stuff.

I'm familiar with rew, dsp operation, time alignment. I've run pink noise spectral analysis in my living room, I'm happy with the response curve and the way it sounds. I definitely agree with room acoustics playing a part in the sound, and my speakers are set where they are after playing with pink noise and spectral analysis. I don't want to convert my analog to digital, process. And the reconvert back to analog. And passing the signal through a million opamps and sliders. I've that too, but the current setup sounds better than either of those did. I'm back to all analog post cd player, and find that my sound is best with little to no tone control applied.

The Wurlitzer mono block tube amps were nice. Pretty sure they are nicer than that monoprice piece of junk posted earlier. They don't have enough power for my big speakers, but they did sound nice with the Boston vr65 at moderate levels. My tube buddy borrowed one of my honey badger amps to play with and was impressed with the speed, clarity, and dynamics of the amp. He was repairing some guys fancy power hungry speakers, and demo'd the repaired speakers to the owner with the HB amp. I considered selling the amp to the guy for $800. Decided to keep it, because it's the best sounding amp I have heard. And it's mine. I made it, and my boy helped. Right now, it's king of the hill.

Levinson makes a $15k transistor amplifier. Have they not heard the gospel of tubes? Or do they think they can make a nice sounding amp with transistors? Maybe there is more than one way to skin a cat. Again, I'm not knocking tubes, room equalization, or the other things you've cited. Just not really sure what you are on about? I'm not pretending to be some magical electronics engineer, and I'm not recording the next rolling stones album. I'm just having fun and posting about it here because my wife doesn't give two shits about this stuff and just wants to play podcasts over Bluetooth from her phone. I'm focusing on transistor stuff right now because that is what I went down the path learning. I'm starting to plan my next amplifier build. Not because I need another amplifier in the house, I definitely don't. I'm doing it because it's fun. And yeah, I do want it to sound good.

Are you designing this stuff? Working with it professionally? What's your background? My interest is in learning electronics and building stuff. What piqued my interest was listening to music and repairing a couple things.

I really like my nakamichi sr4a reciever as well. Very high quality piece. So there. Brah.


sent from Utah.

FM radio is where it's at bro. None of that pussy AM shit.

Damn straight. We got a badass new station here in town kuaa 99.9, but they broadcast low power mono only.

sent from Utah.

Got the buffer finished tested and installed. Had to scrape a portion of a trace away and get creative connecting the input pin for the -18v regulator. But it works. Only listened for a sec cause it's bed time, but didn't seem to impart any noticeable change. Except the cheapo Bluetooth module sounded fuller. Dead quiet, no buzzing, etc. Even made a few nice looking cables for the small signal runs.

Attachment 376717Attachment 376718Attachment 376719

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