![]() ![]() |
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
I noticed when turning the amp on or off, the cones of the speakers literaly move out a good half an inch. Can be barely heard. Same happens when switching sources on the preamp... is this normal operation for a tube amp? Mine has solid state rectifier btw.And would it be safe to connect planar speakers to it if the amp has these surges?
Follow Ups:
This is a nasty one, a sure speaker wrecker if unlucky. You really need a device to mute the output on switching. I have noticed this on tube amps that have been carelessly tweaked, using too-large value feed thru caps, in my experience 1uf is the highest value, any higher and your letting thru very low (sub 10hz) signals at high volume. If it hasn't been tweaked, there may be countless reasons, power supply, loose connections etc. Tricky.
Funny you should mention mute, as even when pressing that button a LOUD pop goes through the speakers.This amp was modded before me, and is wickedly modified, don't think a single thing in it remains stock. I don't have any schematics for it, so not much to work with... where would I look up the feed thru caps?
If it's been modded, then the 'too large value feed thru caps' bit I said is most probably the fault! This is really a job for a techy sort to look at as a bit of knowledge of design is needed to find the parts at fault, if indeed the problem.
The loud pop could also be caused by a voltage going through that shouldn't, ie a short circuited anode cap etc, but really it needs to be looked at (worthwhile if it's an expensive one). Beware, repair shops won't touch modded stuff as it takes a lot of work finding out what was done wrong, esp with no circuit diagram, and nothing could be guaranteed.
A caveat, I'm afraid, beware buying modified equipment(unless it's by a specialist company, or you've tested it out fully)as learners to tweaking make bad errors, I oughta know, that's how I found out lots years ago!
Well that popping isn't really that annoying, it's just that I finished restoring this amp, gutting it completely, enamel coating transformers, mirror finish on cap, all gold/ceramic tube sockets and terminals etc, replacement a few resistors, etc.. everything else looked pretty clean. Now want to rid it off a few bugs sound wise.I looked inside and it is still pretty similar to the original Dynaco 70 running 35w stereo, except solid state rectifier, and a different driver board based on four 6922 tubes. Everything inside looks pretty simple what it does and finding parts should be no trouble. The sound from it is beatiful by the way :)
Could this popping noise come from the preamp? It's a relativly modern digital. OR tubes going bad? I'm still using the ones that came with it and feel like they are getting weak.
Also just noticed that, when "inducing" that popping noise from switching sources quickly it goes away after the first time. That is I'll switch from say Source1 to Source2 there's a pop, but if I switch back within next 1 to 2 seconds there is no pop, and if I keep switching within that short time period there is no pop. Does this help localize on any part in particular?:)
This post is made possible by the generous support of people like you and our sponsors: