How to get a good sound out of JR 149s

[Mandryka]

O

Hi
The 100k pot for each channel of your 520 should be wired out of circuit, to be the same as a power amplifier.

I also have JR149 and they sound great with a Quad 306 per channel.

My Quad 306 have been modified to establish 10ma of current at the base of T2 - I did a thread on this a bit earlier, it uses a LM329
https://www.analog.com/media/en/tech...s/129329fd.pdf
instead of the 6V8 zener at D12 ( d3 in a 306 ) ad hoc providing 100ma To get 10ma I am using a LM317 accessing its adjustment terminal as a current source.
I referenced HiFi engines schematic for a Quad 520F that is very close in design to the Quad 306

This forms my every day system to assess audio. The 149 and Quad amps with a few minor changes are a very good combination when used with
LDR attenuation.

Hope that helps.

Thanks, there’s interesting ideas there there.

[Mandryka]

These speakers have bass drivers which are about 4.5 inches diameter. Has anyone tried subwoofers with them?

[Mandryka]

Or how about stacking them?

If anyone with a pair is near me, I’m in London, and would like to try stacking them, I’m up for it!

[spendorman]

Or how about stacking them?

I double stacked Spendor BC1's, that worked.

I double double stacked (that's four per channel), B&W DM2a's, that worked.

I have two pairs of JR149's, not tried double stacking, yet!

[Mandryka]

I double stacked Spendor BC1's, that worked.

I double double stacked (that's four per channel), B&W DM2a's, that worked.

I have two pairs of JR149's, not tried double stacking, yet!

I hope you’ll try it out and let me know, it could be a really good thing and cheap and easy to accomplish.

[Light Dependant Resistor]

I double stacked Spendor BC1's, that worked.

I double double stacked (that's four per channel), B&W DM2a's, that worked.

I have two pairs of JR149's, not tried double stacking, yet!

Lucky you maybe when you try this have the T27 closer to each other. It would mean having leads at the top
of the top speaker.

[spendorman]

Lucky you maybe when you try this have the T27 closer to each other. It would mean having leads at the top
of the top speaker.

Unfortunately, I'm not going to try double stacking the 149's just yet, some serious things in my life need to be resolved first.

Suspect that double stacking JR149's would work. Only possible trouble is connecting them in parallel, nominal impedance will be half, OK for most amps, but not all.

The reason I went for four DM2a's per side, was that a series / parallel connection, would bring the nominal impedance back to 8 Ohms.

[Light Dependant Resistor]

Unfortunately, I'm not going to try double stacking the 149's just yet, some serious things in my life need to be resolved first.

Suspect that double stacking JR149's would work. Only possible trouble is connecting them in parallel, nominal impedance will be half, OK for most amps, but not all.

The reason I went for four DM2a's per side, was that a series / parallel connection, would bring the nominal impedance back to 8 Ohms.

When comes time, a stereo power amp per channel might be the answer. In my own set up I am presently using 2x Quad 306, presently using one channel of each amp, so a channel per amp is spare
for stacking speakers.

[spendorman]

When comes time, a stereo power amp per channel might be the answer. In my own set up I am presently using 2x Quad 306, presently using one channel of each amp, so a channel per amp is spare
for stacking speakers.

I had thought of that, should really be similar amps, it would not be good, one inverting and one non inverting. I've got four nice Quad 303's, and three A&R A60's, so that's not a problem.

[Barry]

Vertical stacking the DM2As is IMO not successful. If you have the tweeters close together, the bass is confused; if you position the bass drivers together the image suffers badly.