Metal Films in a 183

[dreric]

Hi

I'm starting a 183 and I'm confused by the resistor choices. The layout specifies NTE metal films. I have a local shop that carries NTE but all of the resistors they stock are metal oxide. They have a dull appearance seen in the first picture versus shinning like (purported) NTE's in a Two Rock, second picture.

Seeing the NTE is a re-brander some have speculated that the metal films are vishay BC. Would that be these??:

http://www.mouser.com/Search/ProductDet ... 73NW22K00J

Lastly and perhaps most importantly: Does this really matter sonically? Is there a significant difference between metal film and oxide?

Thanks for the support.

Eric

[dreric]

Here's some progress shots.

Eric

[ToneMerc]

Hi

I'm starting a 183 and I'm confused by the resistor choices. The layout specifies NTE metal films. I have a local shop that carries NTE but all of the resistors they stock are metal oxide. They have a dull appearance seen in the first picture versus shinning like (purported) NTE's in a Two Rock, second picture.

Seeing the NTE is a re-brander some have speculated that the metal films are vishay BC. Would that be these??:

http://www.mouser.com/Search/ProductDet ... 73NW22K00J

Lastly and perhaps most importantly: Does this really matter sonically? Is there a significant difference between metal film and oxide?

Thanks for the support.

Eric

Eric, the glazed blue NTE's that I find locally are 1/8, 1/4, 1/2 and a few 1W. I used the 1/2W ones in my 183. All the metal films that I saw in 183 are the glazed type and I don't think the matte gray finish ones are the same brand or type as the blue ones. Honestly, I can't tell you what the tangible sonic differences would be one way or the other between the two types because I haven't used both. The Vishay PROx series are brown in color.

Another great "blue" option is a Speer/KOA mf1/cc.
TM

[Structo]

Eric,
Take it from me, you don't want those PR01 resistors.
They are tiny even though they say they are 1w.
About the size of 1/4w if that.

The Vishay CCF60 series are very good metal film resistors that are about the size of a 1w resistor.
Kind of a tan body with color bands.
http://www.mouser.com/Search/ProductDet ... 0-2.21K-E3

I only use those metal oxide resistors in the power section as they are flame proof.
I don't think they sound good as a plate resistor at all.

I use the Vishay Dale RN65D series for the plates.

[ampdork]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

[ToneMerc]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

Picture is worth a 1000 words, here you go.

TM

[renshen1957]

Eric,


I use the Vishay Dale RN65D series for the plates.

Hi Structo,

Do you have a link to the RN65D in Mouser? I might try em if I could find them in mouser.com

I swear Mousers catalog search feature is the most non-intuitive feature. I order stuff for my business and if you don't have a part number from a prior invoice you can't find it worth a darn. All I could find in 100K resistor was 1/4 watt

I use PRP metal films for cathode resistors (not from Mouser) at least I can find what I am looking for without tearing my hair out.

[ToneMerc]

Eric,


I use the Vishay Dale RN65D series for the plates.

Hi Structo,

Do you have a link to the RN65D in Mouser? I might try em if I could them in mouser.com

I swear Mousers catalog search feature is the most non-intuitive feature. I order stuff for my business and if you don't have a part number from a prior invoice you can't find it worth a darn. All I could find in 100K resistor was 1/4 watt

I use PRP metal films for cathode resistors (not from Mouser) at least I can find what I am looking for without tearing my hair out.

Part #: RN65D 100K

http://www.mouser.com/ProductDetail/Vis ... dPnKlbw%3d

TM

[Structo]

Yes, the Mouser catalog definitely has a learning curve to using it.
Especially since they really don't show very good images of the products or it may be totally wrong.

I have ordered many things that I didn't want or could use.

After a while you get the hand of what they have and what they don't.

But I always have to order from multiple sources to get what I want.

I have a local surplus place that has those NTE components.
Not sure who makes those metal film but they seem to be pretty consistent.

[diagrammatiks]

the ones in those nte blisterpacks up there if they are the ones used in the two-rock aren't a vintage philips part.

I think that's a beyschlag part.

I was thinking they might be the sfr series now but those are only .5 watts.

The old philips flameproof stuff doesn't have raised endcaps.


[IMG:764:1024]http://i625.photobucket.com/albums/tt33 ... da8dc5.jpg[/img][/img]

[CHIP]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

That's what I used in my 183 build.

[CHIP]

double

[dreric]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

That's what I used in my 183 build.

Chip I see that you followed the component choices very closely, are you happy with the amp?

Eric

[dreric]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

Thanks Shad, if anyone would know it would be you (thanks for all you've shared on the 183)

It's odd that so many of HAD's amps have resistor variety and mostly 1 watt, yet the 183 .5 metal films everywhere. Do you think that the NTE's are a significant part of the tone of this amp?

They have these HW at my local store, I'm used to the 1watts, these look like runts.

Thanks all.

Eric

[CHIP]

NTE 1/2 watt flameproof is what you want... They come in blister packs.
Example part # for a package of 33 Ohm is HW033.
Last time I picked some up I bought a drawer assortment off eBay.

That's what I used in my 183 build.

Chip I see that you followed the component choices very closely, are you happy with the amp?

Eric

I tried to follow component choices as close as I could. No ECI 4.7uf bypass caps. ect.
I never could get my B+ on the EL34 plates as high as I wanted. There at around 435dcv now.
One of the things I really like is the amps touch sensitivity.
I plan on pulling the chassis and replacing the FET jack, change the 1m pots to CTS. Maybe some other misc. things.