NAD: 1964 Fender Tremolux

[archetype]

OP never mentioned wanting to change tonal character, nor was "early breakup" mentioned. I have no idea why that is always the goal. I can't be alone in enjoying a sweet-sounding, clean toned amplifier with character.

1. Right. The OP didn't mention those things.
2. It was a suggestion, since the OP said the amp didn't get breakup until 9 or 10 on the volume. The OP then said no, it's fine as-is.
3. I like exactly what you like, especially with my Tremolux. I also like being able to get a fatter tone without having to explain it to the police at the door.
4. It's all good.

 

[Phrygian77]

@Phrygian77 ….good eye…and no, I don’t recall seeing that extra cap; but we see them in both stacks here, don’t we? And…now that we have eyes on in that area, what is that ‘extra’ resistor sitting in between the plate resistors in each channel….and to what do they connect? I can’t really see the value….220K? It would be of interest to document this circuit if one had it on the bench, it seems to me.

I can't imagine what the purpose is. There is clearly an extra eyelet, and it's there on both channels. I think we can rule out that anyone would have added something like that with wiring under the board, so it's most likely original. I've never seen any Fender that looked like that.

 

[Wally]

I can't imagine what the purpose is. There is clearly an extra eyelet, and it's there on both channels. I think we can rule out that anyone would have added something like that with wiring under the board, so it's most likely original. I've never seen any Fender that looked like that.

could it be some kind of local feedback? One would do well to draw this circuit out if on had it on the bench, imho.

 

[Phrygian77]

could it be some kind of local feedback? One would do well to draw this circuit out if on had it on the bench, imho.

I don't know, but as I look closer, some of the resistors have tighter banding others, so now I'm suspicious of the whole thing.

 

[Wally]

@Ohrygian, I see what you are saying. Those two 220K resistors sitting between the 100K plate resistors do have a different spacing. However, when we look at the two 220K resistors at the channel junction, we see that same resistors, don’t we…with the same spacing of the bands As the other 220Ks?

 

[uriah1]

I had one back in the day. If I recall, not that much power for mine
and grill color was different.

 

[Phrygian77]

@Wally yeah, it's only the 100k resistors that standout as looking different.

 

[brookdalebill]

Nice!

 

[hotcoffeenochill]

@Phrygian77 and @Wally

I appreciate the insights. What y'all are getting in to is way beyond my understanding of things, but I'll see if the tech I take it to would be willing to draw out the schematic so that I can report back.

Any insight as to whether that OT is safe to run at 8 ohms? I know old Fenders usually didn't mind a step in that direction but with a replacement OT I'm not sure. I sent an inquiry to the manufacturer but haven't heard back. The 2x12 cab is a bit much for home unless I'm alone, would love to put it through a 1x12 if I could safely do it.

 

[Wally]

@Phrygian77 and @Wally

I appreciate the insights. What y'all are getting in to is way beyond my understanding of things, but I'll see if the tech I take it to would be willing to draw out the schematic so that I can report back.

Any insight as to whether that OT is safe to run at 8 ohms? I know old Fenders usually didn't mind a step in that direction but with a replacement OT I'm not sure. I sent an inquiry to the manufacturer but haven't heard back. The 2x12 cab is a bit much for home unless I'm alone, would love to put it through a 1x12 if I could safely do it.

Ime, the change to a 1x12 is not going to cut your volume as much as you would need. IF you are looking to push the amp into overdrive, it is going to be loud. If you want rich cleans at lower volumes, turn the tone controls up…..the lower the volume setting the higher you can And should run the tones, imho. This will yield a good sounding, clean ‘bedroom’ amp. Also, Ike, the preamp in that amp is built for clean. Note that the Normal channel is hotter than the Vib channel due to the gain suck that the term circuit has.
So, you don’t have an amp that is anxious to yield overdriven distortion at low volumes….or at any volume really. That is not what Leo Fender was looking for. Also, fwiw, a 5 watt amp through the same speakers as your Tremolox will be louder than your Tremolux…very slightly.
Got an attenuator????

 

[hotcoffeenochill]

Ime, the change to a 1x12 is not going to cut your volume as much as you would need. IF you are looking to push the amp into overdrive, it is going to be loud. If you want rich cleans at lower volumes, turn the tone controls up…..the lower the volume setting the higher you can And should run the tones, imho. This will yield a good sounding, clean ‘bedroom’ amp. Also, Ike, the preamp in that amp is built for clean. Note that the Normal channel is hotter than the Vib channel due to the gain suck that the term circuit has.
So, you don’t have an amp that is anxious to yield overdriven distortion at low volumes….or at any volume really. That is not what Leo Fender was looking for. Also, fwiw, a 5 watt amp through the same speakers as your Tremolox will be louder than your Tremolux…very slightly.
Got an attenuator????

Thanks, I do have an attenuator but I don't have any desire to push this to OD on it's own, so I don't think it's necessary. I'll try the tone control trick. I can run it pretty comfortably clean, it just loses a little bit of life below 3 on the volume dial.

I guess I'm really more interested in the 8-ohm question as all of my cabs except the 2x12 are wired for 8-ohm and I'd like to try it through some different speakers.

 

[Phrygian77]

@hotcoffeenochill it will change the character of the amp. Try it and see what you think though.

 

[Phrygian77]

Since you ready have a replaced OT, you could get a tech to put in one with an 8 ohm tap.

What speakers are in that cabinet? I'd personally look at getting a proper Tremolux cab for it, and put some inefficient 10s in it, WGS Veterans or Jensen C10Rs. That will make the volume control a little more manageable. Sell the Bandmaster cab.

 

[hotcoffeenochill]

Since you ready have a replaced OT, you could get a tech to put in one with an 8 ohm tap.

What speakers are in that cabinet? I'd personally look at getting a proper Tremolux cab for it, and put some inefficient 10s in it, WGS Veterans or Jensen C10Rs. That will make the volume control a little more manageable. Sell the Bandmaster cab.

The current speakers are Oxford stamped 12M6-1. I can't find any info about the -1 code. But both speakers have the same stamp. So I doubt that it was a 4 or 11 where a portion faded.

Edit: Further research concluded that the numbers after the dash don't mean much in the grand scheme of things. The 12 is the diameter, the M stands for 40 watt, and the 6 indicated a 1.5" voice coil.

 

[Phrygian77]

The current speakers are Oxford stamped 12M6-1. I can't find any info about the -1 code. But both speakers have the same stamp. So I doubt that it was a 4 or 11 where a portion faded.

Edit: Further research concluded that the numbers after the dash don't mean much in the grand scheme of things. The 12 is the diameter, the M stands for 40 watt, and the 6 indicated a 1.5" voice coil.

Forget what I said about efficiency and the 10s then.

 

[archetype]

Thanks, I do have an attenuator but I don't have any desire to push this to OD on it's own, so I don't think it's necessary. I'll try the tone control trick. I can run it pretty comfortably clean, it just loses a little bit of life below 3 on the volume dial.

I guess I'm really more interested in the 8-ohm question as all of my cabs except the 2x12 are wired for 8-ohm and I'd like to try it through some different speakers.

The right attenuator will solve two problems. 1. Volume. 2. Matching. Something like a Weber Mass has selectable 2, 4, 8, and 16 Ohm inputs for the head. It doesn't care what the speaker load is, so you can use anything you want to connect it to.

 

[Wally]

Thanks, I do have an attenuator but I don't have any desire to push this to OD on it's own, so I don't think it's necessary. I'll try the tone control trick. I can run it pretty comfortably clean, it just loses a little bit of life below 3 on the volume dial.

I guess I'm really more interested in the 8-ohm question as all of my cabs except the 2x12 are wired for 8-ohm and I'd like to try it through some different speakers.

yeah, push the tones up. Great cleans at low volume .

The current speakers are Oxford stamped 12M6-1. I can't find any info about the -1 code. But both speakers have the same stamp. So I doubt that it was a 4 or 11 where a portion faded.

Edit: Further research concluded that the numbers after the dash don't mean much in the grand scheme of things. The 12 is the diameter, the M stands for 40 watt, and the 6 indicated a 1.5" voice coil.

what are the date codes on those Oxfrods….465 is the Oxford EIA code. That will be followed by three digits. During the ‘60#s, the first digit will be the last digit of the year while the last two digits are the week, of that years. Before 1966, the Oxfords were comparable to Jensens in efficiency. In 1966, Fender requested that Oxford use wider voice coil gaps in the 12” speakers in order to avoid the larger 6L6 amps burning
speakers down…..these speakers were low efficiency and earned Oxfords the nickname of ‘oxfarts’. One must need know the year in order to under what Oxford one has there. The 10” Oxfords did not receive this wide voice coil gap treatment.

 

[hotcoffeenochill]

The right attenuator will solve two problems. 1. Volume. 2. Matching. Something like a Weber Mass has selectable 2, 4, 8, and 16 Ohm inputs for the head. It doesn't care what the speaker load is, so you can use anything you want to connect it to.

I have the MiniMass. But I don't see anywhere in the documentation about it not caring for speaker load.

To be clear, what you're saying is that I would put the MiniMass on the 4-ohm setting, plug the Tremolux in to the MiniMass's input, and then I can go out of the MiniMass in to any speaker ohm without consequence?

 

[archetype]

I have the MiniMass. But I don't see anywhere in the documentation about it not caring for speaker load.

To be clear, what you're saying is that I would put the MiniMass on the 4-ohm setting, plug the Tremolux in to the MiniMass's input, and then I can go out of the MiniMass in to any speaker ohm without consequence?

I can't speak for the Mini-Mass. E-mail Weber. They're responsive.

 

[hotcoffeenochill]

yeah, push the tones up. Great cleans at low volume .

what are the date codes on those Oxfrods….465 is the Oxford EIA code. That will be followed by three digits. During the ‘60#s, the first digit will be the last digit of the year while the last two digits are the week, of that years. Before 1966, the Oxfords were comparable to Jensens in efficiency. In 1966, Fender requested that Oxford use wider voice coil gaps in the 12” speakers in order to avoid the larger 6L6 amps burning
speakers down…..these speakers were low efficiency and earned Oxfords the nickname of ‘oxfarts’. One must need know the year in order to under what Oxford one has there. The 10” Oxfords did not receive this wide voice coil gap treatment.

465-118 and 465-134