Re: M909 specs

William Schnaars

开云体育

Wow that was easy. I’ve been googling these speakers for a while and couldn’t find any specs on them. Thanks! Do you happen to know the maximum power they can handle?

Thanks again.

Bill

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From: [email protected] <[email protected]> on behalf of John van Son <jpvanson@...>
Sent: Wednesday, July 1, 2020 1:48 AM
To: [email protected]
Subject: Re: [DahlquistSpeakers] M909 specs

?

Here you go:

M-909:?

M-909i:?

Re: M909 specs

#5415

Here you go:

M-909:?

M-909i:?

M909 specs

William Schnaars

#5414

Hi I have two pairs of Dahlquist M909’s. One set I bought back in 1988 and the second pair I bought used about 18 months ago. I would like to buy a new amp to drive one set of these speakers but don’t have the specs on the 909’s. I want to buy a new amp but don’t want to destroy the 909’s as I still have a tendency to listen to them loud. If any one has the specs I’d appreciate it.
Thanks Bill

Re: Any DQ-10 Rear Screens Floating Around?

#5413

开云体育

Hello,? I have a spare set of rear screens.

pducote@...?

$50.00 but I will pay shipping?

Phil?

Sent from my Verizon, Samsung Galaxy smartphone

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-------- Original message --------

From: pcb121055@...

Date: 6/29/20 10:49 PM (GMT-05:00)

To: [email protected]

Subject: [DahlquistSpeakers] Any DQ-10 Rear Screens Floating Around?

Hi all.? I bought my DQ-10s well used but intact except for missing the rear screens (grills?).? I am interested in having them for my resto.? Anyone have a lead on a pair?? Thanks! ?

Re: DQ-20i Tweeter dead?

#5412

hey all:

I have two new 4 ohm resistors (from Madisound) installed and with new soldier, the one other issue solved itself. Now listening to Michael Hedges and I feel like I'm inside his guitar. ?Awesome.?

Thanks for all the help!

Re: Replacement Drivers

#5411

I have not had ANY luck with Regnar/Dahlquist site. They have never responded to my inquiries. Madisound sells an upgrade to the Vifa tweeter: I have to replace the vifa's voice coil/diaphram and they are near impossible to find. Madisound has an upgrade to the tweeter:

SEAS Prestige 27TBFC/G (H1212) Aluminum/Magnesium Dome Tweeter

Re: differences between dq-20/20i dq-28i

#5410

Late to this thread (obviously) but here is a datasheet on DQ-28's if anyone needs it.

hfe_dahlquist_dq-6c_18_28_30i_brochure_en.pdf

DQ-28 Re-cap

#5409

I am working on restoring some DQ-28's and need some input. Anyone re-cap DQ-28 speakers? If so, what caps did you use? Thanks in advance.

Any DQ-10 Rear Screens Floating Around?

#5408

Hi all.? I bought my DQ-10s well used but intact except for missing the rear screens (grills?).? I am interested in having them for my resto.? Anyone have a lead on a pair?? Thanks! ?

Re: My Refurbished DQ=10

#5407

Beautiful restoration.? I hope mine come out as good :) ?

Re: DQ-20i Tweeter dead?

#5406

https://www.parts-express.com/

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-----Original Message-----
From: koryrf <koryrf@...>
To: DahlquistSpeakers <[email protected]>
Sent: Tue, Jun 23, 2020 7:47 pm
Subject: Re: [DahlquistSpeakers] DQ-20i Tweeter dead?

I had a friend over and we found that the 4 ohm resistor (upper right of my picture) on both speakers are reading open. ?We couldn't believe that both speakers would have the same issue, so we tested them about 12 times. each time the result was the same. ?Dead. ? Anyone know where to buy replacement resistors like the ones in here (little white bricks)? I can only seem to find the tiny, regular looking ones.

Re: DQ-20i Tweeter dead?

#5405

On Tue, Jun 23, 2020 at 04:47 PM, <koryrf@...> wrote:

I had a friend over and we found that the 4 ohm resistor (upper right of my picture) on both speakers are reading open. ?We couldn't believe that both speakers would have the same issue, so we tested them about 12 times. each time the result was the same. ?Dead. ? Anyone know where to buy replacement resistors like the ones in here (little white bricks)? I can only seem to find the tiny, regular looking ones. I will send the schematic and in it you see how the blue wire attaches to the 4 ohm resistor, but when you look at the XO there is nothing between them.

On my DQ-20 XO board there hidden wire connections on the back-side of the XO board. The missing "blue wire" connection on the DQ-20i XO you reference in the above message (going to the 4ohm resistor then on to the 3uF cap then on to the tweeter) will be found on the back-side of the DQ-20i XO board, along with a few other hidden wires. I recommend you remove XO board from the speaker box and flip it over to find the "missing" connections.

Re: DQ-20i Tweeter dead?

#5404

Definitely odd but a easy fix. That's a win win..

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On Tue, Jun 23, 2020, 8:14 PM John Carpanini <jacarp@...> wrote:

Hi kory

"Anyone know where to buy replacement resistors like the ones in here (little white bricks)? "

Try here:

JohnC

Re: DQ-20i Tweeter dead?

#5403

Hi kory

"Anyone know where to buy replacement resistors like the ones in here (little white bricks)? "

Try here:

JohnC

Re: DQ-20i Tweeter dead?

#5402

The invisible connection on the real XO is the line across the top of this schematic.

DQ-20i-Schematic.jpeg

Re: DQ-20i Tweeter dead?

#5401
Edited

I had a friend over and we found that the 4 ohm resistor (upper right of my picture) on both speakers are reading open. ?We couldn't believe that both speakers would have the same issue, so we tested them about 12 times. each time the result was the same. ?Dead. ? Anyone know where to buy replacement resistors like the ones in here (little white bricks)? I can only seem to find the tiny, regular looking ones. I will send the schematic and in it you see how the blue wire attaches to the 4 ohm resistor, but when you look at the XO there is nothing between them.

Re: DQ-20i Tweeter dead?

#5400

It is also possible that somehow the voice coils have deformed jamming them in the air gaps. Or even better it's a case of hardened up ferrofluid producing a similar result. At this point I'd consider connecting another pair. Perhaps you can then carefully open them up to inspect the coils. If your lucky you can dig out the crusted up crud and run them dry.

DD

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On Tue, Jun 23, 2020, 5:52 PM I.A.Keer via <irakeer=[email protected]> wrote:

On Tue, Jun 23, 2020 at 03:40 PM, I.A.Keer wrote:

Have you tried replacing the Tweeter cap(s) with others of same value to see if these maybe your problem. The tweeter cap (can’t read the value in your uploaded photo) is between the 4ohm and 100ohm resistor on your DQ-20i crossover. On my DQ-20 the tweeter cap is a single Solen 3uF.
TWEETER Cap Clarification:
Original DQ-20 Mid/Tweet X-over (previously sent photo image) clearly shows the tweeter caps as Solen 3uf and 5uf. The DQ-20i has tweeter cap is single Solen 3uF cap. This change (to omit the 5uF cap) is an upgrade option (previously suggested by Dahlquist User Group) when recapping the the DQ-20 for better tweeter performance. I will be making this change as I recap my DQ-20 speakers with new Jantzen Superior Z Caps.
Sorry about any confusion!

Re: DQ-20i Tweeter dead?

#5399

On Tue, Jun 23, 2020 at 03:40 PM, I.A.Keer wrote:

Have you tried replacing the Tweeter cap(s) with others of same value to see if these maybe your problem. The tweeter cap (can’t read the value in your uploaded photo) is between the 4ohm and 100ohm resistor on your DQ-20i crossover. On my DQ-20 the tweeter cap is a single Solen 3uF.

TWEETER Cap Clarification:
Original DQ-20 Mid/Tweet X-over (previously sent photo image) clearly shows the tweeter caps as Solen 3uf and 5uf. The DQ-20i has tweeter cap is single Solen 3uF cap. This change (to omit the 5uF cap) is an upgrade option (previously suggested by Dahlquist User Group) when recapping the the DQ-20 for better tweeter performance. I will be making this change as I recap my DQ-20 speakers with new Jantzen Superior Z Caps.
Sorry about any confusion!

Re: DQ-20i Tweeter dead?

#5398

Your DQ-20i crossover board (previously uploaded) image looks original untouched to my eye. I have attached a photo (see below) of my original DQ-20 Mid-Tweet X-over board. DQ-20 caps values and layout are slightly different, but you can see the similarities in design layout, cap brands, soldering joints, epoxy glue, and wire colors. Everything looks original!

Have you tried replacing the Tweeter cap(s) with others of same value to see if these maybe your problem. The tweeter cap (can’t read the value in your uploaded photo) is between the 4ohm and 100ohm resistor on your DQ-20i crossover. On my DQ-20 the tweeter cap is a single Solen 3uF.

I am orig owner of DQ-20. Currently in-process of rehabbing both speakers (new Jantzen Superior Z Caps, New Mills Resistors, new Dueland 16AVG internal hook-up wire, orig Advent woofers with new foam surrounds, cones balanced and metal baskets/magnets dampened (by Bill Legall at Miller Sound).

Re: DQ-20i Tweeter dead?

#5397

Well I suspect those Solens are not the oem caps. I seem to have a memory of seeing one on eBay years ago with yellow and or black/red caps. The ohm reading point toward the voice coils being good. So perhaps you are lucky and do have a xover issue. I would imagine a schematic is out there. Have a peek at the Yahoo group files.?

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On Tue, Jun 23, 2020, 3:57 PM Sherman Goldman via <qstieee=[email protected]> wrote:

1) Some of the inductors are wound with fine wire, so be careful poking around.
2) None of the resistors looked fried
3) Nothing seems to be disconnected
4) There were manufacturing variations, so wire color and some components may be different than others' without destroying your belief in them being original. Though there weren't as many DQ-20i as something like the DQ-10, so probably fewer construction variations. FYI I have early DQ-10, late DQ-10, and DQ-20.
5) Things of this vintage were hand soldered, and nothing is perfect. If a solder joint separates it won't look it. If you are up to it, a gentle pull on each wire as it attaches to a soldering post (not as it goes in to a component) could find an improbable bad solder joint. If you are not comfortable with soldering don't do this, since if the connection comes off you won't be able to fix it
6) The capacitors with the stylized S logo are Solen, which is a good brand

-----Original Message-----
From: koryrf <koryrf@...>
To: DahlquistSpeakers <[email protected]>
Sent: Tue, Jun 23, 2020 4:29 pm
Subject: Re: [DahlquistSpeakers] DQ-20i Tweeter dead?

Just because I haven't seen this posted anywhere, here is a pic of my high filter crossover. This pic is taken looking in through the hole left after taking the woofer out. There was a fair amount of insulation packed in there that I removed so I could see the crossover. I am assuming this is all original because the guy I bought them from said he was the original owner and never touched them.? Can anyone verify?