Tube Amp Archive

Hey everyone, I'm back again with my NAD 3400. First a bit of background information. I always had the idea that the left speaker had less bass or volume than the right speaker so I checked with a DB meter on my phone and set the amp to MONO and it confirmed what I thought. Back when I did this test...

Sorry TomJS, I come across as a smarmy bastard sometimes....because i am. Didn't mean to sow confusion. That has a hell of a heatsink. Is there forced cooling also? No it was a good joke except I didn't get it at first, but it was a good joke so yeah. Forced cooling, you mean active as in a fan? If...

I see the problem: Too much sand and not enough vacuum.😁 There is no sand in it that I can see, it is a bit dusty but its really hard to get all the dust out since it's quite old dust do you guys have a trick? I don't have an air compressor. Now I feel embarrassed about this message, but do you guy...

Good work! TUBEDUDE is joking... Sand is mostly silica, SiO2. Si is the principle semiconductor from which transistors are made, so solid state stuff is referred to as "sand" by buis enthousiastelingen. O HAHA :lol: :lol: :oops: Well I guess I could expect people joking about a transistor amp on a ...

Those are definitely relays. Your soldering? Did you desolder and resolder them? or are you replacing them? If you just removed them, and replaced them, and the problem is resolved, it may have just needed a reflow of the solder joints, If not you should be able to lookup that NEC relay part number...

TUBEDUDE wrote: ↑Sat Jan 19, 2019 12:06 pm I see the problem:
Too much sand and not enough vacuum.

There is no sand in it that I can see, it is a bit dusty but its really hard to get all the dust out since it's quite old dust do you guys have a trick? I don't have an air compressor.

Is my soldering job okay? This is my second time really soldering circuit boards.

Okay so I'm pretty sure this is one of the relay's, I had to take it out but it turned out its epoxy'd shut but there are 2 small holes 1 on top and 1 on the bottom where I sprayed contact cleaner in them so let's hope that helps! Here are a few images of the part! IMG_1641.jpg IMG_1642.jpg IMG_1643...

Thanks for the tip about the reading material, I will definitely use it! But if there is anyone available I'd really like to ask questions and talk about some stuff trough voice chat too!

Hey everyone, I am still quite new to electronic's but I really want to learn how audio works but I must say that I haven't gotten that far yet by just watching youtube videos. I really want to learn it since I want to be able to repair and build amplifiers and maybe even repair and modify mixers si...

Lauri wrote: ↑Tue Jan 15, 2019 3:23 pm Headphones output looks like to be just series resistors from the speaker outputs to its own relay to a stereo jack. So if the headphones output works I'm back to my first guess that the speaker protection relays are faulty.

Do I need to desolder the relays to take off the cover?

In the partsheet it does say that the headphones have a different relay right?

A 81-622-1-0 RY001, 002. RELAY, MR72, SPEAKER

A 81-628-0-0 RY003 RELAY, MRSZSR, PHONES

I'll check the relay's this weekend if I have time!

Looking at the schematic both A and B speaker connections have their own relays. If you have the same problem with both A and B outputs then the fault probably isn't in the relays but somewhere else in the amp. Unless both of the relays just happen to have the same fault. But anyway you could try t...

Also would this work? [youtube]https://www.youtube.com/watch?v=zqQUEiQgMDA[/youtube]