Mills sound warm & musical the normal wirewounds do sound restrained and harsh. I'm not delighted about the price of the Mills but the sound is too nice to ignore.
I was joking, mostly.
Where do you buy the Mills- direct(??) or.....
Thanks.
I would change nearly every output transformer & choke to Lundahl. Mains transformer is not that important. To equal Lundahl with a conventional transformer you need a huge one - it must be at least 2 times the size of a Lundahl. The Lundahl chokes doing wonderful things to the sound - never believed that it is worth to pay so much for the Lundahls.
Okay you really learn me something here. I will get lundahl transformers.
thanks a lot, I will probably follow all of your advise you earlier gave me about resistors .
Edit: ohhh, they are expensive! So I need two chokes and two output transformers?!?
which model lundahl of ouput transformer and chokes do you recommend for my amp? Cheapest option, or do I even have a choice. I'm really starting in this hobby, so would need a couple of direction. I'm reading a whole lot on the net, but would need some confirmation and for now honestly I have no idea how to choose the right output transformer and chokes
Jay
Last edited:
You really should get the amp running properly before you start a lot of 'upgrades', IMO.
But, if you spend a lot of money, I am sure you will hear a difference!
Oh, tho$e guys!
Why I have to order (Canadian) Hammond transformers from the USA!
Take the AES price, add at least $10 (US) and you have the Part$Conexion price...simple.
And PartsConeXion is about 30 miles from the Hammond plant/warehouse.
Oh, tho$e guys!
Why I have to order (Canadian) Hammond transformers from the USA!
Take the AES price, add at least $10 (US) and you have the Part$Conexion price...simple.
And PartsConeXion is about 30 miles from the Hammond plant/warehouse.
The best hammond prices I have found is a1parts.com in Toronto.
In that case they are reacting exactly as they should do by being proper resistors with ideal temp coefficient. It's the peak current issue that causes alot of the conventional film types to soften up on impulse transients which they cannot handle. Remember, output stages displaying transient overshoot in the o/p tranny (see squarewave test enclosed) will show a reflected spike current in the cathode resistors and this is nasty for composition m/o film type resistors.Wirewounds are perfect for this app and there is no getting away from this fact.
The output stage should hold up whatever signal is presented to it.
If you claim the sound is different by changing the o/p stage cathode resistor types, then one should really examine where the sonic differences are occurring, perhaps in the earlier stages, or blame it on an average quality o/p tranny. The photo hold true for all output stages......from 7W upwards and je higher the power the more care in component choice.
The first casualty with a well designed o/p stage being overworked is the screen resistor ratings acting as fuses. If they blow that would be a warning which has to be investigated.
richy
Attachments
You really should get the amp running properly before you start a lot of 'upgrades', IMO.
But, if you spend a lot of money, I am sure you will hear a difference!
Well, first of all, what are those red circuits doing (those I circle in red on the schematics)? Do I take them off, they are going know where!
Last edited:
First, please double check the schematic against your amp to make sure that R1/C2 in fact are not connected to anything.
Second, did you read Post #41 & 42 ?
Perhaps it would be best to just start changing parts.
Good luck!
oh I dont know why I had told you that I got russian ft-1; what I got is russian teflon ft-3. Are those better and could do well or I should get the mundorf caps?
btw do you receive my pm?
I have doubled check and my schematic is good. I do think I know why the circuits do that.
their is no error for v2 and v3. There is no separated cathode from the heater (pin 2 and 7) on the 6bg4. They make one with two different fonction.
for exemple the cathode(pin 3) of the 6gu7 is independant of the heater (pin 4-5)
Here is attached a schematic I found that really looks like mine that uses the same sort of (weird) circuit...
@ horntube: I didnt find the spec for the Power transformer T1 #512-23629A. I calculated the voltage out. its around 350 vrms center tap so in total 700vrms.
The goal of circuit squared in red on the schematic is to create a dc component of 60 volt on the v2 and v3 cathode.
I marqued that on the schematic 60vdc with 9vac peak to peak and the voltage of l1 r3 r5 r9 and r10.
Theres a ripple of a little bit less then 100mv p-p at the out.
I attached the arranged schema
Well, the FT-3 is only marginal better than the FT-1 but same problems - not very dynamic and pale sound. Don't get me wrong they are quiet good caps but the opposite of that what you want. Take the Supreme or even better the Silver in Oil from Mundorf and you will get Wagnerian drama, explosive dynamics, strong rhythmical flow, blitzkrieg like transients and full loaded bases at the freq. extremes. The Russian teflons are rather easy going & smooth without any edges, lacking at the frq. extremes.
Yeah I liked the DC coupled inverter, too.
Now, how to get Wagnerian dynamics from a noisy amp by changing 2 capacitiors...
If you never experienced a shootout with Mundorf caps, you will not believe it. And something even more weird: With any Supreme M-cap it will play 3-4dB louder!
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.