FYI: Dynaco ST 400 (A reveiw of sorts)

The Donk! · 14th March 2008, 12:24 AM

I just rebuilt a Dynaco 400 and I wouldn't recommend it. I wouldn't recommend it to anyone who considers them self a beginner, and I sure as hell wouldn't recommend it to anyone who works on gear for a living, or regularly; you'll be very mad at yourself for the time you spend. you will waist your life on this unit.

It just isn't worth it.

These amps are horribly designed.

Electrically, and mechanically.

Electrical speaks for its self. (Why are people always replacing finals and driver boards? Crappy design from the get go!

Mechanicals.

Well, honestly, I think the patent office should prohibit such horrible designs.

You will spend literally hours just disassembling and reassembling the amp, let alone time spent on the electrical aspects.

this amp was probably the 1000th piece of gear I worked. And it doesn't work. No matter what. It just doesn't work.

I give this piece of gear a F for every applicable reason to grade it.

It's POS.

Imagine using new parts for everything. And everything is assembled correctly. And it doesn't work!

Somethings wrong!

And it ain't me babe. It ain't me.

I'm sure, allot of people love this amp, and for those of you that do. I'm sorry.

Good luck........

EchoWars · 14th March 2008, 03:47 AM

Quit beatin' around the bush, and say what you really think.

wg_ski · 14th March 2008, 04:20 PM

+1. The best use I've found for Dyna 400 is to reuse the dead carcass. I like the huge heat sink. Drilled for four extra power trannies, and built a more conventional circuit (resembling a PL400, using 3xMJ15024&025 per channel) into it. Sounds way better than the original.

MikeBettinger · 15th March 2008, 01:36 PM

Quote:

Originally posted by wg_ski
+1. The best use I've found for Dyna 400 is to reuse the dead carcass. I like the huge heat sink. Drilled for four extra power trannies, and built a more conventional circuit (resembling a PL400, using 3xMJ15024&025 per channel) into it. Sounds way better than the original.

It has a great power transformer; if you're into transformers.

Mike.

d3imlay · 16th March 2008, 12:11 PM

I never liked the totem pole output design, but it was reliable. By cutting the voltage across the transistors in half the power dissipation was decreased by 4X and allowed them to stay well within their SOA. In the late 80's/early 90's I did contract work for a company that reintroduced the 410 in kit form which is a stripped down 400. I tested all of the driver boards and I know I tested at least a 1000. Very few kits came back and it was always due to assembly errors/poor soldering. I hated to work on them, but they didn't fail.

14th March 2008, 12:24 AM	#1
The Donk! diyAudio Member Join Date: Feb 2008	FYI: Dynaco ST 400 (A reveiw of sorts) I just rebuilt a Dynaco 400 and I wouldn't recommend it. I wouldn't recommend it to anyone who considers them self a beginner, and I sure as hell wouldn't recommend it to anyone who works on gear for a living, or regularly; you'll be very mad at yourself for the time you spend. you will waist your life on this unit. It just isn't worth it. These amps are horribly designed. Electrically, and mechanically. Electrical speaks for its self. (Why are people always replacing finals and driver boards? Crappy design from the get go! Mechanicals. Well, honestly, I think the patent office should prohibit such horrible designs. You will spend literally hours just disassembling and reassembling the amp, let alone time spent on the electrical aspects. this amp was probably the 1000th piece of gear I worked. And it doesn't work. No matter what. It just doesn't work. I give this piece of gear a F for every applicable reason to grade it. It's POS. Imagine using new parts for everything. And everything is assembled correctly. And it doesn't work! Somethings wrong! And it ain't me babe. It ain't me. I'm sure, allot of people love this amp, and for those of you that do. I'm sorry. Good luck........

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
help building an amp of sorts?	Jpoole908	Solid State	16	10th June 2008 09:33 PM
help reveiw this layout please	impsick	Solid State	1	21st October 2007 02:21 PM
GC's in all sorts of boxes....	JDeV	Chip Amps	1	11th June 2003 08:26 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

14th March 2008, 03:47 AM	#2
EchoWars diyAudio Member Join Date: Dec 2002 Location: Left of the Dial	Quit beatin' around the bush, and say what you really think.

14th March 2008, 04:20 PM	#3
wg_ski diyAudio Member Join Date: Oct 2007	+1. The best use I've found for Dyna 400 is to reuse the dead carcass. I like the huge heat sink. Drilled for four extra power trannies, and built a more conventional circuit (resembling a PL400, using 3xMJ15024&025 per channel) into it. Sounds way better than the original.

16th March 2008, 12:11 PM	#5
d3imlay diyAudio Member Join Date: Sep 2004 Location: Ohio	I never liked the totem pole output design, but it was reliable. By cutting the voltage across the transistors in half the power dissipation was decreased by 4X and allowed them to stay well within their SOA. In the late 80's/early 90's I did contract work for a company that reintroduced the 410 in kit form which is a stripped down 400. I tested all of the driver boards and I know I tested at least a 1000. Very few kits came back and it was always due to assembly errors/poor soldering. I hated to work on them, but they didn't fail.